It could probably work technically like that, but i still think it will create a unnecessary distance between those who want to use it and those who don't. Which as far as i can tell for no purpose other than political correctness, that it's good to practice safe sex. While were all adult here and most being 18+ probably learned about practicing safe sex already.
So honestly don't see what this will add to the game other than possibly conflict between sex partners on if or not to wear it, in a virtual sex chat with not STDs.
Seems like you're thinking too much into it. I know it's the topic's name, but the concept of safe sex in a game is ridiculous. The way I see it, having condoms could add a bit of excitement, RP wise (no actual in game effects), with implied dangers of unprotected sex.
Either way, that's just my 2 cents. I personally don't care much about it, especially knowing that it would never be implemented even if everyone wanted it.