Guys...What to do?what to do?

What do u do when u see ur boyfriend with gurls and their talking and uthink he's flirting but when he sees u he goes to u and u blow him off cuz of what u just saw and later he tells u their the ones who went over their to talk to him and ur still mad and he apologizes and u say just don't worry about it its all great and he's. Like okay if u say so and says goodbye