My hope would be that the girls your friend rails behave and feel the same way and their respective partners if they have them know it too, or they’re single and that’s their thing. Maybe they don’t care about herpes, syphilis, chlamydia, or HIV either, because the thrill is worth the risk.
I know that isn’t even mostly the case and most people are behaving in ways they will later regret. But I do think there’s a culture in which we can be more honest and happy with having a bit more love in our lives.
It will take work and conversations like this are a small part of that I guess.