One of my most starry-eyed passionate relationships was with a woman who was 28 when I was 45 (46? damn chronology coming unstuck!). Mindblowing sex. Acceptable to me certainly; I kept forgetting about the age difference. We only lasted a few months together but the age difference had nothing to do with the breakup.
My other relationships, including my marriage, have all been with people not more than five years older/younger than I am. Mostly coincidence, that.