I can only speak for my characters, but one of them is heterosexual and sees it just as a necessity to survive, so he has sex with whoever is close to the game-imposed time limit when he needs it too, since he doesn't plan on actually falling in love with anyone in Vegas. The other is bisexual and polyamorous, but he doesn't sleep with any joe shmoe on the street, he sticks to the small group of people he trusts and cares for.

Out Of Character, I see it like this: DV is a boys-only sex game. We're already bending the IC-ness of most characters apped, so why not go the extra mile and have all the sexy fun we want? Everyone who apps in knows it's just for silly buttsex funtiems, so I think we all just reached some kind of conclusion of "yeah, whatever, we can do this" at some point.