Well some teenagers are legal. Like 18 and 19 year olds, but if there is a big age difference it is still morally wrong.

It won't make you look younger, if anything it will make you look like an old creep.

I'm 19 and a lot of my friends at 18/19 are dating guys who are about 28-30 and sleeping with them. I think it is incredibly gross. Mainly because when they were 18/19 we were about 8 years old. So that's a bit weird when you think on it.