What do I do?

Hey everyone, Ive been dating this guy for nearly 4 months and I think we go together just fine. We have fought over things a few times, but it doesnt really matter cause we usually get over it and be back in love the next morning. Anyway, Im kinda shy and not so social, while he is the center of attention everywhere we go. He is the life of the party. I've only had 6 sex partners and he has had over 200, and he always talk about sex or having sex with other guys, which I am not comfortable with. I've had a 3 sum before with my past relationship, and the 3 sum ended that relationship. He loves my dick and its bigger than his. I just dont know what is up with him when he is constantly checking out other guys saying he would like to do things with them. It sucks cause he isnt suppose to think that way, cause we are together. I just ignore it most of the time. But what do I do. And also, he went to madagascar a few years ago and fell in love with a man there, but because we are together he decided not to go. It sucks cause he is engaged to that man in madagascar, but he is with me. He still calls this man, and this man dont know he moved on. Is my boyfriend a player? What do I do...I just dont know.