Love, Sex, and the Domestic Experiment

Diego’s worldview on love and relationships

The romantic room contains a double-star system, a copy of LOST, and, from one particularly ambitious period, a die for deciding when a couple should discuss renewing its commitment. If you came expecting either a conventional family manifesto or a pamphlet abolishing all relationship rules, you may need to sit down. The furniture is arranged for a third possibility.

Diego wants love to be intense, generous, bodily, sincere, and worth remembering. He also wants to understand the machinery that produces it. He studies pair bonding, jealousy, sexual variety, promises, technology, and incentives because these are the mechanisms through which some of life's best experiences arrive—and through which they can become miserable.

His recurring problem is how to preserve the depth of being genuinely together while allowing a form of life suited to the actual people involved. There is no single relationship label that answers this for every temperament. He has tried different ones himself, and the history matters.

The scientist is also in love

Already in Amor e Probabilidade in 2009, Diego rejected the idea that understanding love from outside necessarily destroys experiencing it from within. The essay examines how attention, uncertainty, investment, and changing attraction influence a bond. Its ethical question is whether such knowledge should be used deliberately, especially where it could benefit both people.

When his imagined romantic objects that analysis ruins the feeling, Diego answers:

Isso é simplesmente falso, a coisa é vivida com total intensidade mesmo quando ela é conhecida, técnicos de computador não tem menos prazer em usar o computador, e bons jogadores de tênis não tem menos prazer ao jogar tênis.¹

English translation: “That is simply false; the thing is lived with full intensity even when it is understood. Computer technicians do not take less pleasure in using a computer, and good tennis players do not take less pleasure in playing tennis.”

He has no desire to win a Nobel Prize for Becoming Emotionally Unavailable. Knowledge is supposed to help produce more good experience, including more good experience with someone loved. His defense includes an important distinction:

a vida não é a respeito de intensidades, mas sim de intensidades BOAS.¹

English translation: “Life is not about intensities, but about GOOD intensities.”

A devastating breakup is intense. That does not make it preferable to a happier relationship whose participants understand their own vulnerabilities. Romantic suffering gets no bonus merely for being cinematic.

The evolutionary analysis also leaves room to disobey evolution. In Using Evolution for Marriage or Sex in 2013, he describes different short- and long-term mating orientations in both sexes, warns against reducing status to money, and treats the modern environment as radically different from the conditions that shaped desire. He wants people to use understanding to find relationships they actually want, rather than becoming more efficient servants of inherited mating algorithms.

The scientist's task is to help the lovers. The genes can submit a comment underneath the article.

Jealousy is not the certificate of seriousness

The early essay Ciúme, written in 2004 and published in 2010, attacks a cultural equation: that a serious relationship is proved by exclusivity and possessiveness. Diego asks why depth and commitment should require feeding jealousy rather than love. He acknowledges biological inclinations toward both possession and attraction to others, then asks which should be cultivated for a better life.

The later autobiography of his relationships gives this argument an experiential form. In February 2023, after several years exploring monogamous or publicly monogamous arrangements, he published Monogamy Made Me Miserable. He describes the emotional burden of treating mate guarding as a duty: a large field of other people becomes a field of potential violations.

His short formulation is:

Monogamy made me care about things in a way I normally don't. And it made me care about things I didn't care about.²

He did not describe himself as magically free of jealousy in open relationships. What changed was which events counted as betrayals, how much monitoring seemed necessary, and how much suffering an event produced. Boundaries, rules, and trust remained. Exclusivity ceased to be the measure of every success or failure.

This was also a rejection of a particular masculine performance. He had wanted to test whether he could succeed within the sexual hierarchy praised by the right. Having done so, he questioned why someone else's definition of masculine victory should determine the emotional conditions of his life.

His conclusion was personal rather than a ban on everyone else's arrangements. In the same essay he writes:

It's ok to have rules and vetoes in your relationship.

It's ok to have a rule that says "we are monogamous"²

The enemy here is being pushed into a structure that makes the participants miserable, then being told that the misery establishes their virtue.

Two stars, with room for a sky

Diego's own preferred image in that 2023 essay was:

I think of relationships as a two star system with planets and meteors and moons.²

The two stars are himself and his girlfriend. Other ongoing relationships are planets; briefer encounters are comets; people connected to those partners are moons. He treats the primary pair as a difference in kind, not merely the top two names on a spreadsheet of otherwise interchangeable affiliations.

This is important for understanding his use of polyamory. He is not describing relationship anarchy, a prohibition on vetoes, or a duty to distribute attention equally. The central bond has its own character. Its participants can agree to constraints while permitting other connections.

He also distinguishes identical permissions from what he regards as equivalent emotional costs. In discussing earlier arrangements, he reasons from different male and female patterns of jealousy and permits the resulting agreements to be asymmetric in their wording. His idea of a workable relationship begins with the specific people, their psychologies, and what they will actually agree to.

And he refuses to turn a declaration of identity into another prison:

I reserve the right to become Mono again tomorrow if I feel like it.²

Astronomy is the current model. It is not a treaty preventing the astronomer from moving the telescope.

Commitment needs somewhere to stand

The desire for freedom runs alongside an equally substantial desire for commitment. Diego dislikes the atmosphere in which each partner is continuously shopping for a better offer. A relationship becomes impoverished when everyone is preparing an exit instead of investing in the person already there.

His 2017 essay Trying to Solve Childless Committed Relationships asked how a couple could sustain commitment when children were not the project, religion was not a shared foundation, and alternatives appeared everywhere. He wanted to shift the incentives toward:

make this person’s life as amazing as you possibly can and allow them to do the same for you, because you are together in this boat, and neither is going anywhere³

His proposed design was unusually literal. He wanted a finite, renewable commitment outside both church and state, with costly exit mechanisms. He favored four years, followed by a probabilistic extension before the renewal discussion, using uncertainty to resist the tendency to stop cooperating as a final round approaches.

Yes: a relationship essay with an endgame problem, an escrow possibility, and dice. Cupid has been asked to attend the mechanism-design seminar.

The proposal belonged to that 2017 inquiry, which he explicitly opened for feedback. Its place in the portrait is the ambition it reveals: to make durable cooperation possible without merely inheriting a marriage template. Beneath the machinery was a simple desired behavior—two people improving each other's lives, treating their bond as something worth maintaining.

His later return toward openness did not erase that ambition. It changed his answer to what the bond should permit.

The dividing line is trust

His recurring demand of a partner is honesty. In the 2023 account, the worst pain came from broken commitments and deception. He distinguished that pain from the much smaller discomfort he sometimes felt about an allowed connection with another person.

In February 2026 he restated the distinction:

I don't mind people having multiple sex partners, I had open relationships for like, 12 or 13 years.

But I really, really, really, really, REALLY do mind people lying.⁴

Sexual conventionality is therefore a poor substitute for the quality he wants. A person can perform respectable purity and still deceive. Another can be open about an unconventional life and make a loyal partner under the agreements that actually exist.

His 2026 discussion of previous partner counts likewise separates sociosexuality from an inability to bond:

We still have our pair bonding structures fully functional. We just like fucking on top of it. Just like you may like chess. Or jazz.⁵

He does have limits and preferences; his acceptance of sexual variety is not an endorsement of every possible pattern. In that post he becomes concerned when a pursuit of sheer numbers crowds out love and sustained relationships. The positive criterion is the intention to build something together:

the main deciding factor is whether the person wants that relationship to thrive and win 🏆.⁵

Desire, for him, is welcome. Falsehood is not improved by wearing a wedding dress.

The eternal romantic and the glowing rectangle

His most tender recent account is Adapted To a Different Time in April 2025. Rewatching LOST, especially the love story of Desmond and Penny, he tries to understand his longing for earlier forms of connection.

The declaration is direct:

But I am an eternal romantic. I am an eternal romantic and I am always seeking pre-internet love.⁶

This comes from a man whose intellectual and social life was transformed by the internet, who found partners through it, and who has no general desire to abolish modern technology. What he misses is the experience of people becoming deeply involved within a bounded social world, without a planetary inventory of alternatives always glowing nearby.

His diagnosis of what went wrong is:

It transformed love into attention and transaction.⁶

He is drawn to islands, festivals, and situations that remove the phone and bring a finite group into sustained contact. He wants presence, discovery, and shared history to regain their force. The desire for openness in a relationship coexists with dislike of an environment that continually weakens attention to the relationship itself.

He has also explored optimistic possibilities. His explicitly labelled 2023 steelman of contemporary dating considered whether better matching systems, virtual companionship, and more ways to enjoy life might allow different people to find arrangements that fit them. That was an exploration of the strongest positive case, not a declaration that all his concerns had vanished. It shows the question remains larger than returning everyone to one historical household.

Children are a separate invitation

Love, commitment, sex, marriage, and parenthood do not arrive as an indivisible package in Diego's thought. He has long examined how the first three might work without children. By December 2025, his position on the individual reason to become a parent was especially clear:

Do you want the set of experiences that is associated with having a child? Do you want the child to have that set of experiences with you?⁷

For himself, he answered no. He distinguished wanting the parental relationship from being persuaded to reproduce for a legacy, genetic duty, or a religious command. After revising the urgency he assigned to birth rates, he wrote:

I think wanting the experience of having kids trumps every other consideration in importance, and if you don't want to, I have no moral reason to make you do it.⁷

The room consequently remains an experiment in the good life of particular people. Diego wants the lovers to enjoy each other, tell the truth about what they want, choose commitments that have substance, and avoid converting a social script into needless suffering. He wants beauty, adventure, a dependable bond, and the feeling that a real person has become irreplaceably significant.

The star system may change. The wish to be delighted by somebody, and to make life more delightful with them, has been furnishing this room for a very long time.

Further doors

• Ciúme (written 2004; published 2010) and Amor e Probabilidade (2009): jealousy, romantic knowledge, and the ethical use of that knowledge.
• Using Evolution for Marriage or Sex (2013): his account of mating psychology and its relationship to chosen goals.
• Trying to Solve Childless Committed Relationships (2017): the detailed commitment experiment.
• Monogamy Made Me Miserable and A Deep Inquiry Into My Last 6 Monogamous Years (February 2023): the return to an open relationship model and his retrospective understanding of the change.
• Adapted To a Different Time (April 2025), Reconsidering The Birth Rates (December 2025), and Do Women Body Counts Matter? (February 2026): the later romantic longing, parenthood position, and account of sexual variety with pair bonding.

Continue: Who Gets to Be Family?