Yeah, that's right. The same thing (more or less) happens in many games. And, yes, few (if any) handle it well (or decently, at least). But, I don't know, this one was particularly disappointing to me. It's both the rushed sex scene and the fact that the MC is behaving completely ouf of character. I mean, the guy is a bit of an asshole, and has shown that he can be violent, but there is a huge way from kicking some moron's ass to raping the shit out of your aunt.
Well, on the bright side, the mother scenes were not so bad, except for the fact that the 'wet skin' textures looked really bad (like she was mutating into some kind of lizard or something).