Please Help Me Advice Needed!! read down below....?

I had a party, and we were all sittin around and this guy was my ex boyfriend, he go's Sarah will you go out with me and he had a girl friend at the time and thats what i said, so he flips open his celly and calls her and brecks up with her, so i said yes and and we held halnds on a walk we took andwe were alone so i got to cuddle with him and we were watchin one of the jason movies and we just were cuddling and holding hands and every thing was perfect except i felt sorry for his ex........ What should i do?????