I NEED ANSWERS

Ash

SO MY BOYFRIEND HAS A SISTER THAT IS NOT REALLY HIS SISTER AND HE LEFT ME FOR HOURS FOR HER AND I DONT KNOW HER AND I TOLD HIM I FEEL UNCOMFORTABLE ABOUT THE SITUATION AND HE SAID THAT I SHOULDNT BUGG OUT BECAUSE THEY GREW UP TOGETHER BUT I HONESTLY DONT CARE BECUASE I NEVER MET THE CHICK BEFORE LIKE WE GOT INTO THIS ARGUMENT OVER THE SITUATION SHUD I GIVE HIM SOME SLACK OR IS THIS A SERIOUS PROBLEM!!!!