I am 43, and my partner is 28. We have been together 5+ years. When we look at other guys and talk about if they are attractive or not, he is always looking at the guys around my age or older. We both feel comfortable with ourselves and with our relationship. Age is just a number, but I sure wouldn't want to be dating an 18 year old. There has to be a maturity level that exists, and I don't think 18 year olds have that.