One thing that's always felt a little more adult about the Witcher games, was how they were willing to let you mingle in with the other cast members and take them to bed if it makes sense at the time, much in the same way that Mass Effect let you do it, only without so much of that relationship building.
In the upcoming Witcher 3, sex has a much bigger part to play and in-fact, if you were to sit through all of the mo-capped sex action, you'd be there for the best part of a day.
Why so much sex? Because CD Projekt believes that it helps add to the intimacy that Geralt and his chosen companions share and therefore, if something happens to them, it makes you more likely to go after them.
At least in theory.
"We are establishing that your character was intimate with this woman recently in order to plant in your mind, that, at the very least, he must enjoy her company," Senior Game Designer Damien Monhier said to the Guardian. "Through sex we have shown that this is a person who Geralt would be compelled to chase after if she went missing."
He also pointed out that sex is a natural part of life and would be a high point for many characters in a world filled with monsters and endless battling. Perhaps he has a point.