I'm in the same boat. My mom went off and got engaged to this dude.
He's so damn nice, it makes me feel scummy. Both because of the people who have asshole "stepfathers" when they don't deserve them and the fact that someone's nice to me. His family has been really accepting and all that jazz. I haven't had a "family" since I was around 3 years old. Not to say he's approving of my hikki habits - Just like any normal human being would be, he's always trying to get me to come out of my shell. But he's a pretty awkward guy, and it comes out clumsily. I appreciate it immensely, but I sure as hell don't deserve it, though, and it makes me feel like shit, how he can be that overlooking regarding all my faults.
It's all very weird.
Anyway, I just deal with it if/when I'm forced to socialize. I mean, when you've got a free ride like most hikkis, if they're not ice-cold to you, then you have no right to complain if your family wants you to spend time with them. But if they're assholes, then screw them, because that's just unnecessary considering.