Is it normal for ur friend to have sex with you without you knowing? plz help!!

Ok, so i had some friends over for a party, and everybody was doing their own thing, and i was so tired that i went into bed, and i was woken to see my friend my friend (she is a girl and i am a guy) sitting on my dick! The second i opend my eyes she jumped off and pretended like she was sleeping! She denyed it when i asked her but i know i saw her do it! And i know it halpened because i saw her vagina wet and i had a boner. My dick was also wet when i woke. I dont have a problem really, shes very hot, and i have thought about having sex with her, so it didnt bother me at all, but is it normal for this to happen?