Do all men cheat?

My boyfriend that I’ve known for about 17 years however we been together a year. In that year he was still talking and sexing his x girlfriend for the first 6 months, now he’s on Craigslist looking for women, and yet tells me “baby we gotta keep our connection.” Everything in me wants to smack his teeth out his mouth, but I’m gonna remain a lady continue to be the person I am get my finances together and just move out