BF Problems HELP!!!

My BF is always talking about messaging other "cool" girls and talks about his exs and I don't know how to tell him I rather talk about us or just talk to get more familiar but I don't want to be that crazy jealous girlfriend and I don't want to sound petty he's always telling me he likes that I'm not on him 24/7 and gives him some space but I feel like talking about other girls is something I want to talk about with my BF