Is he giving you information about his past? I mean…if he can dish it he should take it. He shouldn't be making snide comments about you and nor should he be bringing up details that you don't feel comfortable disclosing. From here out, you can simply let him know that if anything from the past comes up that may be relevant to this relationship comes up, you will share (and do) but otherwise, there are certain things that you need to disclose in your own time. You learn about people over time, you don't interrogate them.