will he cheat?

i have be in a reletionship with my bestfriend for 4 years, whether it is dating or sexual. We are very young im 18 he is 19. Now in the past he has dated 2 other girls while we are together. he doesnt say were together but we are. the first gir he cared for a lot not even a month into the reletionship he cheated on her with me. it started as that one time and grew into all the time, he finally broke up with her and me and him were back to normal, then the second girl came a long and yet again not even a month into the reletionship he cheated on her with me again and again it was consistent. then me and him dated again and we broke up a year later(now) he is now in another reletionship. which in the that year we were still together. and he is like oh im not gunna cheat this time all that stuff. Do you think he will? like we have been sleeping together for 3 years straight like we are so close so together. and this chick is almost 3 years younger then him. like what are the chances of him cheating on her 2 with him cheating on ever girlfriend he has had since meeting me with me. I kno he will, but what do others think. Like once a cheater always a cheater?

maybe 'once a cheater always a cheater' doesn't always apply... but jeeeez he's treating you like something on the bottom of his shoe! however much you/ he may dress it up, he's cheated on you and not only once. go and find someone who is proud to call you their girlfriend and who will ALWAYS put you first.

If they cheat, and don't take time off from dating to figure out why they're doing it and fix whatever is broken inside that leads them to cheat. Yeah, he's gonna cheat.