I'm still talking to my boyfriend's ex-girlfriends
Why do you still talk to your boyfriend's ex-girlfriends?
I can learn more about my boyfriend. I heard that his ex-girlfriends are the best people to ask about him.
You should learn about your boyfriend from your own experiences with him and not on his past relationships. If he is no longer in contact with his ex-girlfriends, you should respect your relationship and no longer communicate with them as well. Continuing to engage with them can bring conflict towards your relationships.
You're just jealous of me and he doesn't care about it.
Have you talked to him about this? If he doesn't know, it might upset him. You should have a conversation so you can learn more about him if that's what you want.