it really isn't a big deal. 2 years isn't a big difference. If he is mature enough for you and you like each other enough go for it. Who really cares what high school fags think anyways.
On another note, i once went out with a girl 2 years older than me. Not because i'm a pimp, she wasn't all that great. But it wasn't a big deal. Kind of funny i hate her now, though.