I went to shower this morning and was startled by my penis having pulled into my skin-fold.Why?

My wife had a traumatic experience when she was very young.She has never had an orgasim.We have been married over 34 years.She stopped reacting when we had intercourse about 5 years ago.We talked about it, even seeing a counselor and both decided it was not that important to cause a problem in our marriage.We agreed to set aside a personal night once a month to seduce each other.This lasted until she began menapause.She dropped it like a hot potato. I still tried to seduce her and she went along with it until I noticed she was just there and not participating.We talked again about it and we both agreed we would not have intercourse as a part of our marriage.She is 50 and I am 54.There were times that she would seduce me and we would have intercourse, but I always waited on her.I took advantage every chance she gave me. The times between have grown longer, to the point of our last being over 6 months ago.I had, in the beginning, satisfied my need for arousal via the internet. This I did about every few days. After a month or so,I began to feel a deep guilt.I stopped.I have not had an arosal since.No problem.Until this morning.When I went to shower, I noticed my penis had slipped into my skin-fold.I was circumcised as a new born, and have never had this happen before. What caused it?

I have given the most concise information I can,so you might see my sexual background.