My wife was 7 years younger than I,
and we met when she was 17. I've
met others at that age, and certainly
think that that's an acceptable one,
at least for SOME. On the other side,
I doubt that I was ready for a relationship
of any seriousness, before when it happened
to me, around 20. Some people mature
emotionally much quicker than others.
I just don't see that a simple age can
clearly express this. Yeah, it's pretty clear
to me that there is a line where it is NEVER
acceptable. But it's not at 18.
As to ages being similar, I've seen a lot of
harm done to one another, in just such relationships.
Same with age being different. Age does not make
a predator. Using people makes a predator.