They probably know something that you don't know. You say he's been your boyfriend for 5 years.
When are you going to get engaged and married.
After 5 years you should at least be engaged.
If he's cheating on you with these other girl's he doesn't have any intentions of marrying you. Are you American?
If you are you should learn about the Haitian Culture and eventually you'll find out why those girls were looking at you in that way.