Age difference in dating?


Hi all! So i'm currently dating/hooking up with someone who is 7 years older than me (i am 21 & he is 28) and i'm having so much fun. He lets me rant & be myself & he's good in bed lol however, my entire family hates it. how do i get them to come around to see him how i see him? also what's the biggest age difference you can manage in dating?