When the second season of House of Cards closed with Frank Underwood double-tapping his ring on the Oval Office desk, viewers scrambled to explain what it meant. It was such a small gesture, and one Frank makes on the regular. But behind the Resolute Desk, it took on a new, menacing subtext.

Frank makes no moves without careful calculation. Season 4 brings another one of his deliberate gestures leaden with meaning, this one at the Underwoods’ breakfast table: He offers Tom Yates, who’s just spent the night with Claire in the Underwood home, his daily plate of apple slices.

So begins a new phase in the Underwoods’ relationship, which the most recent season of the Netflix series portrays as a thoroughly evolved, robustly healthy open marriage. In Episode 11, after learning that Claire and speechwriter Yates have agreed to halt their affair during the Underwoods’ presidential campaign, Frank delivers a speech to Claire that he might have cribbed straight from a role play in a polyamory workshop:

He should stay on, because he can give you things that I can’t. Look, Claire, we’ve been a great team. But one person—one person cannot give everything to another person. I can’t travel with you. I don’t keep you warm at night. I don’t see you the way he sees you. It’s not my permission to give, but you’ll do what’s right for you. But I want you to know, if you wanted, I know you’ll be careful. And I’ll be fine. I mean, if we’re gonna go beyond marriage, let’s go beyond it.

For a man who has blackmailed, entrapped, and killed to preserve his own megalomaniacal path to power, putting a partner’s autonomous needs over jealousy is a shockingly selfless move. Frank’s response is doubly generous since he himself had a near-romantic encounter with Yates in Season 3. Not only that, but he recognizes that it’s not his permission to give. In all other arenas of his life, Frank draws his lifeblood from manipulation; he’d rather die than lose control. In his marriage, he’s content to watch Claire pursue her own path to happiness, even if it means bringing another man into their house.

The apple moment and Frank’s speech are worth pausing over because, throughout the series, sex is more often wielded as an extortion technique, a bargaining chip, or an instrument of violence than enjoyed as a component of true intimacy. The only overlap between sex and love viewers see—Remy Danton and Jackie Sharp; Rachel Posner and Lisa Williams; Zoe Barnes and Lucas Goodwin—occurs outside the traditional institution of marriage. Even within the Underwoods’ marriage, the most tender sexual moments arise in their extramarital liaisons—Claire and Adam Galloway; Frank and his classmate at the Sentinel—or when they’re hitting it with a third, as in their sweet double-teaming of Secret Service agent Edward Meechum. House of Cards makes a convincing argument that a strong marriage needn’t depend on sexual fidelity and that emotionally fulfilling sex needn’t concern marriage at all.

That’s Frank’s perspective, anyway. Since the first season, when he went to great lengths to keep Barnes as a sexual partner even aside from her utility as a reporter, Frank has gradually grown out of his desire for sex. “Everything is about sex. Except sex. Sex is about power,” he famously said, quoting an unnamed source, in Season 1. Frank loved holding his power over a noob journalist’s head, and he got off on screwing Meechum, his subordinate, for the power trip. Now that he has the power of the Oval Office, Frank satisfies his needs for intimacy in other ways: ordering Doug Stamper around, having late-night phone chats with Claire, and yes, sharing his apples with Yates.

An open or polyamorous marriage seems like an ideal setup for Frank and Claire. They’re often apart on the campaign trail, and there have long been signs that their sexual proclivities weren’t quite aligned; last season, Claire was crestfallen when Frank wouldn’t rough her up in bed. When you’re a formidable intellectual and political match with a partnership strong enough to stand without the support of sexual attraction, that’s not enough reason to end a marriage.

Which raises the question: Why don’t more politicians and public figures, whose lives are impossibly busy and often lived apart, go the “beyond marriage” route? Often, when a political sex scandal breaks, rumors flutter about a secret open marriage. Did Anthony Weiner and Huma Abedin have an agreement? Did Silda Wall Spitzer know about Eliot’s penchant for sex workers? Maybe not. But, as Hanna Rosin wrote in Slate when House of Cards first began, if they did, they’d be excoriated:

Were the Underwoods a real political couple in actual Washington and the double-affair scandal broke, news reports would depict theirs as a marriage of cold, calculated convenience—the Clintons, but worse. Francis would be revealed as secretly gay, turned on by women only when he can use them for a pure power play. Claire would be a Lady Macbeth figure, orgasmic when mutually scheming but devoid of anything like warm-blooded love. … “Friends” would offer that they have no actual proof that the Underwoods ever had sex.

But like most depictions of a couple at the center of a scandal, this one would be crude and unsatisfying because, as with the Clintons, we can sense that the Underwoods’ relationship is more than just instrumental. True, we never see them have sex, but there is an erotic charge between them, or at least a deep intimacy, symbolized by that nightly shared cigarette.

It’s impossible for some to imagine a “beyond” marriage like the Underwoods’ or how Rosin and I interpret the Clintons’: a partnership that’s intimate and enriching and not just for political gain, but involves little sex and/or sex outside the marriage. In a January undercard debate for the GOP presidential nomination, Carly Fiorina stoked that fear of the unknown in her audience. “Unlike another woman in this race, I actually love spending time with my husband,” she said. The next day, on Morning Joe, she continued: “If my husband had done some of the things Bill Clinton had done, I would have left him long ago.” In pop culture, open marriages hew to one of two archetypes. There’s the rarer House of Cards model, in which the partners truly embrace the freedom-in-security of their relationship, recognizing that the benefits of a lifetime partnership need not cease when sexual attraction fades or strays. The Good Wife, on the other hand, envisions a political marriage more in tune with popular persuasion: one purely for show, where the relationship has all but evaporated and extramarital dalliances are expected but still begrudged.

Today, misgivings about open relationships extend beyond the strict moral code of politics: Just last week, the New York Times published a biological anthropologist’s skeptical take on Mo’Nique’s open marriage, which Dan Savage roundly dismissed. Though House of Cards’ depiction of nonmonogamy strikes me as the warmest, most compassionate arc of the series, the carefully negotiated arrangement that is Claire and Frank’s marriage serves to support the show’s larger narrative of a sociopathic couple that prioritizes power over passion. Depending on who’s watching, their open marriage and Frank’s queer sexuality can complicate and humanize the Underwoods, or it can solidify their characters as depraved utilitarians with no solid moral compass. A show less cynical than House of Cards might have used their progressive relationship as a lens for interpreting the political marriages we love to probe and mock. Instead, the show seems to conclude that the polyamorous Underwoods are void of emotional attachment, divorcing sex from love and vice-versa, with hearts too frozen to burst into flames when a spouse’s desires lead her astray.