Let’s get this out of the way first: You’re right, IUD, sexually transmitted infections (STI) do happen to people in monogamous relationships. People cheat, people lie, people contract, people transmit. A 2015 study found that people in consensually nonmonogamous (CNM) relationships were no more likely to contract an STI than people in monogamous relationships. The reason? If a person in a monogamous relationship screws around and doesn’t use a condom, they can’t ask their partner to start using condoms again without drawing attention to their infidelity. If someone in a CNM relationship asks their primary partner to start using condoms again — because a condom broke or fell off or didn’t wind up on a cock for some other reason—they’re drawing attention to their fidelity. Moving on…
Right again, IUD: Babies do seem to be the only STI many men are worried about. Australian researchers conducted a large study about stealthing — the deeply shitty, rape-adjacent practice of surreptitiously removing the condom during intercourse — and they were shocked to discover how common this deeply shitty practice seems to be.
“The researchers estimated in advance that approximately 2% of the sample would report having been stealthed,” sex researcher Justin Lehmiller wrote in a blog post looking at the results of the study. “In fact, 32% of the women and 19% of the men surveyed reported having experienced stealthing … A majority of both groups reported discussing the event with their partner afterward, and most also reported feeling emotionally stressed about it. A majority also considered stealthing to be a form of sexual assault. These results suggest that stealthing is not a rare occurrence and we would do well to study it further.”
The researchers didn’t ask heterosexual men about being stealthed and, as Lehmiller points out, there are some scattered reports out there about women poking holes in condoms before sex or retrieving them after sex. We don’t need a study to tease out the motives of these women — they want to have a child and don’t care whether their partners do (and that is not OK) — but we could use a study that asked heterosexual men about their motives for stealthing. One question we should put to these assholes: Are they more likely to “go stealth,” i.e., to sexually assault a woman, if they know her to be on some other form of birth control? Or are they just so wrapped up in their own momentary sexual pleasure that they don’t give a shit about babies or any of the other STIs?
Moving on to your actual question…
Can you lie? Of course you can. Should you lie? In the case of a casual sex partner who might not have your best interests at heart, i.e., some total rando you want to fuck but aren’t sure you can trust, I think you can lie and should lie. This lie doesn’t do him any harm; it’s not like you’re telling him you’re on birth control when you’re not. And if telling this lie inspires some rando to be more careful about keeping the condom on (sometimes condoms fall off by accident), then it’s a lie that made the sex safer for you and for him.
And if you get serious about someone you initially lied to about having an IUD — if some dude makes the transition from hot rando to hot boyfriend — and he reacts badly when you tell him the truth, just say (or text) this to him: “I could have waited to fuck you until I was sure you were a good guy. But then you would have missed out on all the awesome sex we’ve had up to now. Would that have been better? And by coming clean now, I’m basically saying that I think you’re a good guy that I can trust. I know that now, but I didn’t always know it because I’m not psychic. Now, do you want to raw-dog me or do you want to complain?”
Q: My girlfriend opposes sex work because she believes it oppresses women. Early in our relationship, she demanded to know if I had ever paid for sex because she couldn’t be with me if I had. And I told her the truth: “No, never.” She didn’t ask if I’d ever been paid for sex. (One guy, he blew me, no women were oppressed because no women were involved, it happened twice.) Do I need to tell her?