As long as they're both adults and they're both happy, who cares and what business is it of mine?
I bred my "heir and a spare" during a miserable marriage to a peer-aged man; now I'm in it for the relationship, which is much more contingent upon how well our personalities fit together than upon our ages. Toward that end, I've dated peer-aged men, men 12 years younger than myself, and am presently involved with a guy 19 years older.
Besides, beauty is in the eye of the beholder. No one thinks anything of it when it's a 50 year old man with a woman in her late 20's. There's nothing wrong with having a thing for older ladies.