Need someone to talk to, Sorry so long

My SO and I have been good friends for about 5 years and just started dating about 5 months ago. When we first met we did sleep together and didn't have any physical contact after that for about 4.5 years but we talked all the time on fb. Now that we are together and he knows a lot more about me and my past (I was very permiscuous when I was younger) he sometimes makes jokes about him not being the only guy to make me get my couch wet with cum, and how loose my vagina is. I love him so much but the comments really hurt me. I have told him a hundred times how much it bothers me and he thinks that just bc he is kidding that it's ok to keep doing it no matter how much I ask him to stop. We are ttc our third baby, first together and sometimes I really have my doubts when he does this. Idk what else to do. I have gotten upset and cried and mad and told him to stop until I'm blue in the face. I'm totally lost. I really need some help here.