Or maybe he just learned early how hot Mrs Robinson types can be.I had a younger friend who had a "Mommy fixation". His mother died when he was about 13. I saw him date a girl his age once when he was around 18. After that, he was always with much older women. Older as in his mother's age, and they were all married (Also usually very good looking).
So maybe it's not so much that these encounter traumatized them, as that they were traumatized in the past, and this is the reaction to that trauma.