Changing standards of what is considered "scandalous"
Watching "Guess Who's Coming to Dinner" and it occurs to me that while the interracial relationship is perceived as freakishly weird, the fact that the 37 year old distinguished doctor picks up a young 23 year old thing at a "Dean's party" after lecturing at a university is seen as perfectly normal.I admit I am quite shocked when I hear about romantic relationships involving large age differences (and I'd consider 37 and 23 to be largely different). Such things scandalize me to a surprisingly high degree. I've never been in such a relationship. I think the biggest age difference I've had with a partner has been less than 4 years (and I was in my 20's before I had any romantic relationships at all).
Whenever I hear about such a "May-December" pairing, I always think: so when I'm 37, does that mean I get hit on 23 year olds? (Well, now that I'm married such thinking is of course extremely hypothetical in nature.) Well, actually, it doesn't shock me that a 37 year old would hit on a 23 year old. But getting into a relationship with a 23 year old...23 year olds already seem very young to me and I'm only 33. But of course if I were single (which I am definitely not), maybe 23 year olds wouldn't seem so young, even if I were 37.
Of course different people are looking for different things in relationships. So if it works for you...