what do i do

so i broke up with my boyfriend because i need time to learn to love myself. although we probably shouldn’t we still hang out and have sex occasionally. he took my virginity and was the first guy i have ever done anything with and i really felt i could trust him. i told him that i really didn’t want others knowing about what we do, people start rumors and get in my business and i’d rather just not deal with that. he agreed and was respectful about it until the other night. he has a friend that he’s super close with and they’ve been friends for years. he went to the beach with that friend and while we were on facetime my ex just kept going into specific details about when we had sex i kind of brushed it off at first but he just kept on doing it. i wasn’t really upset that his friend knew because i know they’re close but i still feel really disrespected. at one point in the conversation i made a joke saying his dick was small because we always just joke around like that and his friend was like “obviously it isn’t that small if it makes you scream.” it annoys me because it really isn’t any of his friend’s business and he promised not to say anything. am i overreacting ?