When you say that it hurts when he fingers you, I assume you mean that he’s inserting a finger in your vagina.My first question would be, does it hurt when you insert your own finger? If it also hurts when you do it, then you may have an infection. If it only hurts when he does it, then you would want to check to see whether his nails or skin are jagged.I’d also wonder if he’s being too rough. Also, make sure that you are adequately lubricated before he inserts anything inside you. A dry finger on a dry vagina is painful.Again, if the pain exists no matter what, then see a gynecologist and check yourself out for infections. Best wishes.