As usual, I agree with bird! Mostly...
Small age differences are irrelevant — more irrelevant the older you get. But larger ones, despite all the anecdotes and exceptions to the rule that do exist — I can’t help but wonder, with a large (10+) year age difference in a long-term romantic relationship…. Why? What on earth would the man in that couple see in that? And eventually, what man would want to deal with things like hip replacements, hearing aids, menopause, gray hair…. Sexy, right? Maybe if it was an exceptionally good-looking or maybe wealthy older woman/younger man combo, well, that might make both parties happy, and more power to them if that’s the case. That's their business and I would just be happy for them. But for your average older woman/younger man in a serious relationship that is more than a fling, and although I would not judge such a couple, I would wonder why a little?? Probably because I am shallow. If I was single and all of a sudden got hit on by someone that much younger I would die of shock first so the relationship would automatically be doomed.
For my part, I’m with Gracie Ruth on the whole man vs. boy thing. I much prefer men (of any age!) than boys (also of any age) who can be a little bratty sometimes, and frankly, I have my hands full taking care of various children, not that I don’t love them, I do! But for a relationship someone with some maturity is much preferable to me.