I was in a relationship with a guy 10 years younger than me, I was 40, he was 30 when we got together. Random people used to ask if we were twins. Very weird, that. There wasn’t much difference in our basic lifestyles. There were more issues around religion, gay activism, and what we found interesting than anything you could pin on age per se.
We split up at 20 years when we’d just grown apart.
So now I’m back to singledom, and find my threshold is guys around 40, maybe stretching to 35. But I’d much prefer someone in their 50’s or up, better yet around my age (62). Anyone under 35 may be eye candy and definitely can fall under the “hot” label, but they would drive me nuts as BF material. I like the maturity of more... ermm... mature guys.
That said, I don’t think it’s weird, bad or impossible to have a working relationship with an age gap of 20 or 30 years, as long as no one’s getting used and both parties care for and respect the other. If you have the mental and emotional connection going, most everything else can be worked around.