Issues with coming out to my family (lol completely unheard of, amirite)?

Alright, so, here's the problem:

I'm pansexual, agnostic, and in an online relationship (of a sort) with another girl.

This Fall, I'll be living with some of my close family while I attend college. This particular part of my family is Christian and while they're extremely tolerant, I'm still not sure as to how they'll react to this development. (Especially as I've told them otherwise when I was younger.)

Some of them have made vague comments a while ago that if I was atheist/gay/whatever, they'd be okay with it, but some of their more recent comments (not directed towards me) have made me uncomfortable and doubted the truth in what they've said before. I don't want to lie to them about who I am and when I go on without saying something to them when they make those comments, I feel like I AM lying. I'm not sure if I'd be able to hide any of my feelings while I'm living with them either. Is there a good way to address this sort of thing with them? Do I let them find out by themselves?