I think the reason it doesn't bother me is because it was totally normal when I started high school (1970). Most of the senior girls were engaged to older guys to the point there were rules about wearing their rings. In my own class (6 year school) in '76 at least one senior girl was already married (no, no kids). My own cousin married a guy who was 7 years older they started dating when she was 15. But I do understand why people are horrified at that kind of age difference.