Marriage

Sorry but long- My partner and i have been together for 7 years and we have 3 kids, He had proposed about 3 years ago with no ring when we were in bed and I said yes than I found out he had slept with a childhood mate of mine. We broke it off for a few months but everytime he would come see the kids he would plead for forgiveness, I eventually took him back but he said a few days ago he never wants to get married EVER! Am i selfish that i really want that someday and cant get passed it?