Okay some people have this argument, "Hey. my parents are 5-10 years apart and they are just fine", but what they fail to realize is that at that age, the difference between a 18 year old and a 14 year old is huuuge. I mean, a 16 year old and a 17 year old are completely different, they even act different depending on grades. As you grow older, it becomes much more of a free for all. Around age 25 it stops mattering what the age difference is.