Guy swears up and down that I'll marry him one day...?

Tell him you have no desire to be one his three latest girlfriends and that telling you about them is not making you more attracted to him in a girlfriend/boyfriend sort of way. This may have started as some form of come on that because of your blunt style lead to friendship or he could be just blowing smoke to impress you like he impresses the guys. (immature) Know any of the other women.... would they talk.... see if he clams up if you tell him you are not impressed by the number of notches on his bed post.