By letting your boyfriend role-play a rape scene with you is not only detrimental to your own well-being but also endangers women out there on the roads. You are "desensitizing" your boyfriend towards the horrors of rape. He may start having these urges towards other women and end up in prison.
Atleast on two occassions, that is when you were asleep and he coalesced with you without you knowing it... and when you asked him to stop an*l-but he did not; were actually 'rapes' in accordance to our "law". To state it differently, your "fantasy" has already become a "reality'. Your well being lies in your decision to eliminate this fantasy before some greater damage is done to you (or any other woman's) body. Please seek a consultant's help. These things are manageable. I wish you good luck