Why won’t he talk about other girls around me?

Asked: Why won’t he talk about other girls around me?

So this guy and I used to be friends, then he asked me out on a date.Long story short, it didn't work out and things have been kind of awkward ever since.A few months ago one of his friends told me that my crush gets jealous when he hears I'm with other guys but he has never told me he liked me.Anyway, he and I were hanging out for the first time in a long time tonight and everything was great until my crush's friend brought up a girl who wants to **** him.My crush got really mad and told his friend to shut the **** up.It was obvious that he didn't want to talk about this girl in front of me even though I offered to give him advice about her.But it's been so long since we hung out, why would he care about talking about some girl in front of me?