I think it depends on the individuals, and love doesn't consider such things. MrsW is one year older than me..........
I know a couple with a 14 year gap. He is now 63 - looks older, and with three kids under 10. She is much younger looking than her 49 years and he is usually taken as the grandfather - this happens all the time when they are out together.
But then again, wealthy old blokes can pull women much younger than themselves. A bloke at work has just pulled this off and he's not even wealthy. He is late fifties, she is mid twenties.
Ok this making me feel better, I'm seeing an amazing lady but there is 11yrs difference im the older at 35