Most likely the priest did what He did out of some sick need. It's easy to understand that could happen. It's part of the human plight. As a part of our humanity, the most noble of us often do the stupidest things. We can forgive him and go on.
Physical pleasure is a normal response to stimulation of nerve endings in that area.
Because it felt good does not make us homosexuals or scars us for life. We had better tell the truth. The young men need to know that emotions are related to the goodness or evilness they attribute to their experiences. If they attribute to much evil to something, they will feel an extreme negative emotion. Satan's Tactics Satan the great deceiver is behind all this commotion about nothing.