Ex asks me about my sex life

So I have my ex for a class and me and another girl where talking about something sexual and he got in the conversation since he talks to the girl I was talking too and I somehow said something in the conversation implying that I’ve had sex. (I was a virgin when we where together) and then when she left from her seat he started asking me question like when was it , how many bodies do you have, how many times& he also asked if I cheated on him when we where together...etc. I was the one that broke up with him.it was the weirdest thing cus I haven’t had a conversation with him in over a year and he has a what it seems very serious girlfriend. Was that kind out of line for him ? Or is it reasonable for him to ask cus I personally don’t care about what my ex’s are doing after I’m done with them especially if it was over a year ago.