There is this thing in the real world called hookup. It's usually refers to a one time casual sex, that may or not evolves into something more. It's quite a common thing actually. Sure, a girl knocking on your door selling cookies most likely won't start to have sex with you out of the blue, but it is an 18+ game, and having this over all those slow burning hj/fj/bj steps and night creeping bullshits over tons of episodes, is rather refreshing.It really doesn't add to the immersion that you can have sex with literally every woman you see almost immediately. The only woman it remotely makes sense with is Kate and the woman from the bar. There is no build up with any of the other characters. With Kate it makes sense, there's a built in buildup with her. She's fantasized about this for years and is apparently a freak in bed. I can buy that Mara wants sex, but I can't buy that she jumps into bed the first night you're there.
The game is good for what it is, but it's story isn't very deep.