The problem with this is the generation difference. They're both adults, so it's less... weird, but the fact of the matter is that they are both from two different generations. The one dude is old enough to be the other's dad. Seriously. That is weird, regardless of how much an adult you are. Those kind of relationships aren't healthy. If you are incapable of being with someone in your own generation (Right now I am considering a generation to be 15 years forward), you need to probably reconsider your life.
I hate mostly everybody, especially ones around my age. You don't see me running off to date a fifty year old lady because "love doesn't have a number", which, oddly enough, is only said by the people that want to be involved with someone that is capable of being their father/mother.
My sister is romantically involved with a 62 year old man. She is 24. He is old enough to be her grandfather.
It's not my place to disallow people to do this, but they are weird for doing it, in the same way that people who enjoy watching girls/boys getting mounted by animals is weird.