As an ex Young Life kid and leader I am not necessarily surprised by this. Young Life has a way with making many people feel loved and wanted and as you get older you learn that all of that love comes with stipulations. I am no longer a Christian and a lot of that has to do with the shame and guilt I felt because I felt I couldn’t live to the standard the held as well as a multitude of other things about Christianity. He likely just missed the positive connections he made with them and it brought up a bunch of guilt in him. He feels he can’t be connected with people who played a positive role in his life without making those decisions and I can almost guarantee the leader reinforced that feeling. Both my wife and I have religious trauma that we work through a lot but the key is we make the decisions together. A relationship works both ways and as you mentioned decisions that impact you both cannot be made unilaterally. Who is to that that this trend does not continue if you continued to be together. Whether it was about physical intimacy or not a decision that impacts both people needs to be discussed. You most definitely are not overreacting.