It's a horrible double-standard, but it's the one the world still largely functions on. Look at the game. The first sexual experience in the game is with Kira, the porn star. Then it's basically Alice, who loves to party and is obviously no virgin. That leaves Ann and Lisa. Lisa is a virgin, while Ann seems like she doesn't have nearly Alice or Kira's experience with men. The game itself and it seems a lot of the players (myself somewhat included) buy into the notion of that sentiment, at least on a fantasy level. Personally, there's a part of me that wants a path where Max and Lisa are both virgins, until they cure that together. But I could still have fun with a route where Max is a total slut. I'm less cool with seeing Lisa do the same, even though I know it's a double-standard. But seeing her be a slut in one path is going to color my view of her in others.