He has no right to ask you anything about your ex or any other male friend. He gave that right up when he walked out. Don't let him control that part of your life. If you want to talk to a male friend, then do it. He wants to go out and sow his oats but he wants you at home waiting. NOPE! Not going to happen.
My H was involved with his coworker and that was okay (not to me) but one day he was over and I received a text message from a male friend and he saw it and asked who is so and so. I said a friend. After that he started to come around and chasing me again. Because he thought he was going to lose me. I just laughed on the inside.