I was in a relationship for four years with a man who was more than 20 years younger than me, it was serious from the start. We had that huge age gap but every relationship has it's specific problems and that one doesn't necessarily have to be thought of as any more serious than any other. As for the guys who think we all want to have the shit fucked out of us for hours on ends don't you think we want that with guys our own age too? They might not be able to fuck six times a night but they make up for it with experience so that evens it out so don't kid yourself you're hot shit in bed :) We're fully sexually mature, we know what we like, we know how to do it superbly and we've had so much practice at it, that's why we want lots of sex.
Incidentally (and I hear the same thing from lots of 'older' women) we don't seek you out, you seek us out and it's not just for the sex, you seem to enjoy what we have to say, the way we act and that we're confident with ourselves and with our sexuality, and most of us have dealt with the issues of our youth.