My boyfriend likes to have sex with me in my sleep, and it really bothers me. I think this is a really important question. Your boyfriend is not only doing something that bothers you, he is doing something without your consent, which is illegal. Anytime one person has sex with another person against their will, it is rape. For most people, this situation is not as clear-cut as a woman who is attacked and raped in a dark alley.
Rape can occur within a relationship, even marriage.
Sometimes it's difficult to imagine that your partner, with whom you share many good times, could do something so disrespectful. The second point that I want you to think about is your reaction to his behavior. You made it clear that his actions bother you. It sounds like his behavior is strictly selfish on his part, since you receive nothing from it. To give him the benefit of the doubt, his actions are most likely a result of a lack of education.