Ran into a bug where, playing as a female survivor, I came across a scavenger while in the forest who wanted to trade food for sex. I had a condom and had him put it on. The scene says he put it on, but when the deed was done the condom was still in my inventory and my stats say I'm full of cum
Edit: Now I see there are multiple scenarios for a forest scavenger. The one with the bug was the one where the dude is eager and runs for you. You then lead him into a bedroom to kick things off. I ran into a second one, this one with a gravely laugh, and did the same thing. I still have the condom in my inventory and in my stats it still says I've only ever had sex with one male.
Edit2: Ran into the scavenger that originally traded antibiotics for a look at your tits in the Forest. It looks like the scene with the first forest scavenger repeated. Or maybe it's more accurate to say the first scavenger played the antibiotic scavenger's scene since they both say they left Riot Gear after everything's done.
Edit3: Antibiotic scavenger had a round where he traded bullets for sex. Had him wear a condom and not only did it not work, I ended up pregnant from it. Also I this point I should have at least 5 male sexual partners (3 if the repeats from the Antibiotic scavenger don't count), but it's still at 1.
Edit4: Choosing the "Have sex with Katy" option at the Theme Park gives me the male scene since it mentions having a cock.
Edit5: When going to the Fire Department with Akane, she threatens to kick me in my nonexistent nuts. She also says her mom would have tried to set me up with her once she realized I was a boy despite not being a boy.