mutual masturbation

Is it normal for girls to experiment with sex together when they're not lesbian?

Sam asks:

A couple of years ago I was over at my best friends house and we were in her living room ready to go to sleep and we were just talking and she asked me if I masturbate and I told her I did and then she started to rub her clitoris and then she started to rub mine. After that she asked me if I had ever kissed a girl and I said no then we started to make out and stuff. I know I'm not a lesbian but what we did was a lot of fun, is this normal for girls to do this sort of stuff together?