I would see nothing wrong with me, at age 68, having a relationship with a lady in her 20's... tall, blonde, stacked. My wife of 48 years, however, might not see it that way!!!! :>) I get to kid my wife each year from August to November that she is just as old as I am. Then, in November, I jump ahead of her one year. That's about right for age difference....
When we were married in 1966, she was 19 and I was 20. Back then, girls were "of age" at 18. Boys weren't until 21. Being only 20, the State required that I get my parent's signature before they would issue a marriage license. Both parents have been long gone. I still am upset with them that they ever signed that permission slip!!!! :>)
In today's society, we do see good relationsips where there is significant age difference. We all are watching the same television, spending time on the same internet, seeing the same movies... generations are much more "connected" than we were 50 years ago. I don't believe a 10 year difference in age, today, is nearly the challenge it would have been two generations ago.