W.O.W. you are doing a dance right now. You think you know what he is going to say or how he is going to react and he is probably feeling the same way. When he tells you something you react the way he suspected you would and not the way he needs you to right now and so you are both wary of each other. So when you ask him something he is on guard probably with the attitude of “when I tell you something you get mad why do you ask or want to know”.
Maybe it would be best to “write” him a note apologizing for your reaction. “I am sorry I reacted with such harsh words when you told me about the girls. Although it is not what we do, and it is not recommended to mingle at such a young age for obvious reasons, it is normal and quite understandable. I am very glad that you told me. You can talk to me about anything. I am new at this chapter and I might make mistakes but I love you and I am here for you so give me the chance to adjust to it.”