I think I was molested by my brother in law last night.?

I was at my brother's house with my sister and her husband (my brother in law). Everyone was drinking (I wasn't, I'm 16), so we had to stay over because nobody was fit to drive. We were sleeping on the floor, my sister was next to her husband and I was on the other side of him. We're close, so I didn't think it was weird. I woke up in the middle of the night and his hand was down my pants, messing around. Not going inside, just messing around. I kind of maneuvered out of the way. I'm pretty sure he was asleep, and maybe he thought I was my sister? I just feel gross now. I haven't told anybody because I don't want to get him in trouble or anything. But I just feel so weird about it now. Was I molested or do you think it was an accident?