Sex is not something owed in return for going on a date. Those types of situations are difficult to sort out. She feels violated. He feels like he did the right thing even though she may have said no and meant it. This seems to be very common in date rape situations.
Date rapes are the most common type of rape committed.
It tends to be very devasting because the victim has been harmed by someone she previously trusted. Victims have to learn to trust people all over again. This is not an easily accomplished feat. Date rape cases are also hard to win in court, very few cases are ever reported. Of the reported cases, even fewer wind up in an actual conviction.