Re: Was it rape?

Your one act of physical resistance was enough to end it, could a drunken boyfriend completely into it ignore 'baaahby, stooop..." sure.  Is he a bit of a pig....yup.  Did he know you weren't digging it, yes.  Did he seem regretful, yes.  Do you ever enjoy it that way?  No.  So take that as an affirmative to tell him what is up and not put yourself in that position ever again. 

I do not think this makes him some secret abuser, unless there are many other signals, I would not make an entire character assassination based upon the incident.  You both acted stupidly, him selfishly.  I am quite sure he was thoroughly enjoying himself despite you which makes him about 93% of most men I know...ha.  Please be careful not to let other's bad relationships with men color whatever truth you may know that is well beyond what anyone in this forum could possibly grasp from one isolated incident.  Take this as a wake up call to quit having intimate time that is not enjoyable for you and obviously makes you uncomfortable and feel victimized, despite your seeming agreeableness.  By your own admission you have a good friendship and loving relationship -- if this was a glaring magnifying glass upon an area that needs to be addressed use it as such and move forward into a healthier, loving relationship with your boyfriend.

Everything is bigger when you've been drinking, and it would seem both your uncomfortableness with the act and HIS delight in it, despite probably knowing well before this that it was not something you liked whether or not it had ever been vocalized came to the forefront.  Use it as a stepping stone to right this area that has obviously been out of balance for some time now.  If it goes beyond this and you find it only the tip of the iceberg then examine whatever light bulb has gone off and make a serious examination of the entire relationship and whether you should continue it. 

Good luck.