This piece was originally published in Slate on Oct. 26, 2015.

When Nicole, who’s 25, moved out of her house last year, she didn’t think about the Roku device she was leaving behind. Her live-in boyfriend had cheated on her while he was on a trip for academic fieldwork; she found out that he’d continued the affair on the down-low, long-distance, for weeks after he got home. The breakup had been raw and messy.

Some time later, Nicole looked at the history on her family’s Comcast Xfinity account. Her ex had been watching his shows with a cable login she’d shared with him during the good times. “I guess I felt betrayed on a number of levels, and that betrayal was facilitated by technology—i.e. email, Facebook,” she told me. “So this felt like another way technology was screwing me, or letting him take advantage of me. … I was slightly baffled how he had the nerve to cheat on me after three years and then still exploit my family’s resources.” Still, she was “too over it” to confront him and prolong the breakup. His free TV was safe until he got around to returning the Roku a month later.

Sharing passwords to video-on-demand sites is a telling step in contemporary coupling—a contemporary version of leaving an extra toothbrush in your partner’s bathroom. However small, it’s a gesture of trust and generosity; it suggests that you’ll spend more time together than apart. On streaming platforms that keep track of users’ viewing histories, it becomes a tiny window into your partner’s desires and habits. And, if and when the relationship withers, it’s another formal link to sever.

According to a May 2015 Exstreamist survey of 400 streaming video-on-demand users, 49 percent of viewers aged 18 to 29 share at least one account with someone outside of their home. While HBO and other streaming video providers might not exactly encourage password-sharing, most users don’t see it as a breach of ethics, or don’t care if they’re responsible for an infinitesimal profit loss for a huge corporation. But the moral code of using an ex-lover’s account—especially if she or he doesn’t know you’re still watching—is blurrier.

Jacob, 32, and his previous girlfriend broke up on good terms; his ex still has a profile on his Netflix account, which he doesn’t mind at all, though it does strike him with a twinge of “quiet, unexpected familiarity” every time he logs on and has to choose between her name or his own. “I think it’s the simultaneous sense of persistence and distance, the way that it keeps her in my life as a mere fragment,” he says.

If a relationship ends in betrayal and lingering resentment, like Nicole’s, it seems like twisting the knife for the offending party to hang onto the password just to avoid paying eight bucks a month. But the moral balance can flip. Diep Tran, 27, watches TV through her ex’s mom’s cable login, and she doesn’t know—or care—if her ex knows. “He was sleeping with someone else towards the end of our relationship, so I consider it an alimony of sorts,” she told me. “Considering the shit he put me through emotionally, the least he can do is give me free HBO/Showtime/Starz/FX.”

Sharing a streaming account leaves a lot in the open. One 36-year-old Netflix subscriber found out that her girlfriend was living with her paramour—not, as she’d alleged, her sick grandmother—when her DVDs stopped getting shipped to her house. When she looked at the queue, it was chock-full of what she calls “lez primer movies” such as Bound and But I’m a Cheerleader—the kind you rent when you’re dating someone who’s in her first queer relationship, and you want to indoctrinate her with some important cultural touchstones. “Sure enough, the address was changed to the girl I knew she was running around with, who was also ‘straight’ until they got together,” she says.

A lover’s Netflix queue isn’t a fail-safe window into her sex life, but it can be a strong hint.

Johanna, 28, says her girlfriend broke it off because “she decided she wasn’t gay.” And then? “She watched three seasons of The L Word on my Netflix account before I figured it out and changed the password.”

A Netflix queue isn’t a fail-safe window into an ex’s sex life, but it’s a strong hint.

Sharing an account on a platform that keeps track of a user’s history can facilitate a kind of automatic surveillance that’s unwelcome for both parties. If you see an ex pick up where you two left off on Season 3 of The West Wing, you might start wondering if your whole relationship amounted to a blip in the Bartlet presidency and your ex’s TV schedule. Erin Coulehan, 26, gave her Hulu password to a guy who’d gotten her into The Mindy Project but had to miss the season premiere while on tour with a band. “It was a huge thing for me, like bigger than exchanging keys,” she says. She realized later that she could see, in the account history, what he watched and when: “It was a little strange, like the microchips you get put into animals, so I tried to avoid it.” When they broke up, she couldn’t stand the thought of him watching Hulu with a new boo and changed the password—just a few days before The Mindy Project became exclusive to Hulu.

Demetria Cipriano, 27, noticed that her ex still had a profile on her Netflix account several months after they’d broken up. “I removed it immediately, thinking there was no way she had been still using it,” Cipriano says. “The next day, I get a sarcastic text message about [how I’m] shutting her out of my life.”

Video-on-demand passwords can function like sexually transmitted infections: You might only give your login to one person, but once it’s out of your hands, it spreads. A Slate colleague still uses a college friend-of-a-friend’s Hulu login, though she hasn’t spoken to the owner in years, and she let me poke around the profile settings. Through the power of word-of-mouth and loose streaming ethics, there are now 36 devices registered on this one account.

And yet, despite how promiscuous our logins might be, a shared streaming account can be much more than a cost-effective entertainment vessel—it can become a symbol of commitment to a shared life. When Stacey, 28, considered getting back together with a boyfriend who’d broken up with her twice before, but kept initiating reunions, she was put off by his admission that he’d signed up for a new Netflix account on his own. They still shared a joint account, and the password was their initials and anniversary. “Later, I realized why it bothered me so much that he told me he got his own Netflix account in the same breath that he told me I was the love of his life and he couldn’t live without me: He was hedging his bets,” she says. “He wasn’t all-in. … He hadn’t changed, and our relationship wasn’t going to change. I said no.”

In some circumstances, an ex who sticks around on a streaming account can be a perpetrator of financial abuse. “My abusive ex-partner still has an account on my Netflix and I’m not about to change my password because I’m literally afraid of the abuse I know I’d receive via text— similar to what I got after I stopped paying her credit card bills,” one woman told me. “It’s also a privacy issue: As long as she has an account, for instance, I can’t add a DVD plan, because then she could find out where I live.”

Shared accounts can be a low-pressure way of staying in each other’s lives.

The best way to avoid online TV-watching drama during and after a relationship? Get a joint account that you both pay for, and cancel it if you break up. Consider it both an investment in your relationship’s equal power balance and a kind of prenup—a safeguard against post-breakup exploitation that you hope you’ll never have to use. If you think you can still be friends after you’re dunzo, you can keep sharing the costs. After Jill Raney, 31, and her partner broke up more than a year ago, they agreed to continue sharing Netflix and Hulu accounts, and both are happy with the set-up. “We can see what each other watches on Hulu and we don’t really talk about it,” Raney says. ”Once, she clicked on my Netflix profile instead of hers by accident, and she texted me to ask what I thought of Sense8. We’ll keep doing it until it doesn’t work anymore for whatever reason. We’re also successfully co-parenting our dog.”

When this system works, it can be a low-pressure way of staying in each other’s lives. Mandy Lineweber, 26, shared a Netflix account with her ex and her ex’s twin sister for years. “If I was watching something and see Law and Order in the ‘continue watching’ section, especially on a weekend morning, I’d think, ‘Oh, hi Taylor! I hope your hangover is going well!’ “ she says. “Actually, Netflix should introduce a messaging system for this purpose.”

Or, if all this emotional turmoil doesn’t seem worth it for the limited pleasures of online TV streaming, take some words of advice from one 23-year-old woman who saw that her ex was still watching “weird History Channel specials about aliens and really old episodes of ‘90s Japanese cartoons” on her family’s Netflix account two months after their breakup. Via text, she asked him to log out, and when he denied using the account, she changed the password. Now, she says, she doesn’t play the Netflix-and-Hulu-et-al. game anymore. “I found myself a super nerd who loves theater and books instead.”