I don't have a problem with lesbians, I just don't like how she touches me. Like one time we had a sleepover, and she thought I was asleep, and she reached over and started touching me. I don't know what to do. I don't wanna ruin our friendship but I wanna know the truth.
Why? Because no one's allowed to touch you in ways you don't like - not even your friends. And if you don't say anything, she'll think you don't mind, and she'll keep doing it.
Next time she tries to touch you, tell her, "Please cut that out. I don't like it." If she tries to sneak attack you at a slumber party, tell her, "Hey. I'm still awake. Quit it."
If she freaks out about it or gets angry, stand your ground. Even if it means not hanging out with her anymore. If she can't learn to respect your physical boundaries, then that's a pretty great indicator that she's gonna make a terrible friend in the long run.