What are your thoughts on privacy between relationships? I recently started seeing someone and she let me know she’s trans. No issue with that, as I am non-binary myself. However, she didn’t want me to share this with anyone. Okay. I understand. It’s not mine to share. However, my partner asked me point-blank one day if she’s trans and I told him no. It felt bad and weird to lie to him. Also, in our talks about sleeping with other people, my partner’s rule is "swap papers" (STI test results) with people who have vaginas and "use condoms" with people who have penises. With her being on hormones and whatnot, condoms won’t always work and I don’t know how to ask about it to make sure my partner’s wishes are being fulfilled while respecting my girlfriend’s desire for privacy? At the same time, if a guy were having trouble getting hard, the go to wouldn’t be “let’s skip condoms then.” I'm just not sure what the right thing to do is.

New Girlfriend's Pretty Private

Zones of privacy for metamours... and primary partners and paramours and spouses and special guest stars and rubber gimps... I'm generally in favor of that, NGPP, so long as no one is being deceived or betrayed.

Zooming in...

There are two separate issues here, NGPP: your new girlfriend's right to control her own story—who she comes out to, when she comes out, if she comes out—and the rules about safer sex you hammered out with your boyfriend prior (presumably) to opening up your relationship. And those aren't "his" rules. If you agreed to "papers/assurances" from partners with vaginas and "use condoms" with partners who have penises, NGPP, they're your rules too.

Now the fact that your new girlfriend is trans doesn't (or shouldn't) impact your boyfriend, NGPP, so lying to him when he point-blank asked if she was trans after she'd asked you to keep that private was the right thing to do. (Saying "I don't know" or refusing to answer would've been as good as saying "Yes, she is.") But immediately after lying to your longterm boyfriend to protect your brand new girlfriend's privacy, NGPP, you should've gone to your girlfriend for guidance: "Look, I totally respect your right to privacy but I'm not comfortable lying to my boyfriend. How would you like me to handle this?"

Your girlfriend might argue that her trans status is none of your boyfriend's business... and I'd be inclined to side with her... if you weren't thinking about making an exception to the rules (your rules) for her dick, NGPP, and rationalizing that exception as an effort to protect your girlfriend's privacy. Hormones may making it harder for her to "obtain and sustain" an erection, as they say, but that's irrelevant: she's got a dick, she wants to fuck you with it, she's gotta wrap it up. Them's the rules. When condoms work for her, great. When they don't, pivot. If she can't stay hard with a condom on then you'll have to do something else, NGPP, just like you would with a cis male partner who couldn't keep it up for whatever reason. You seem to be suggesting that since you can't ask your boyfriend about making an exception for your new girlfriend without getting into "hormones and whatnot" (and, you know, dick), then you might be able to go condom-free with her without your boyfriend's okay consent.

Nope. Your primary/longterm partner's wishes are clear and easy to fulfill: use condoms with the new girlfriend. Failing to use condoms with her would mean you prioritized your girlfriend's ability to get hard, stay hard, and get off over your longterm boyfriend's concerns about safety. And that would be a betrayal.