You should never do anything you are not comfortable doing, and you have the right to say no. Even if you are dating someone, you still have the right to say no, if you are not comfortable. When my boyfriend and I started becoming intimate, I told him right up front, if anything makes him uncomfortable, and he doesn't want to do something, to say no, stop, or he doesn't want to do something. I also let him make the first move, which frustrated him, because he thought I wasn't in to him or something, but that's a whole other topic. The point is, if you're not comfortable, no is no, and you have the right to be firm on that, regardless of where you're sleeping.