Is he too old?!?

Alright so basically I am turning 19 in about a month. I have b en talking to this guy for a while and he is an amazing man. He is even a marine!!! The only thing is that he is 25. That is a 6yr difference. Neither of us mind the age difference but I don't know if my family will approve of it. I am very mature for my age and we are both on the same page as far as what we want out of life. I just don't know if the age difference is too much or not please help!!!