My last boyfriend was 3 years older, so age isnt that much of a problem. 4-5 years would be my limit, ish.
It all changes once you get past teenage years, though. Age dosn't become an issue.
I'd only date someone my age.
I'd allow someone to be 1 year older, MAX!
2-3 Years is fine by me but no more.
I'd allow 4-5 years but thats it.
5-7 years, just like you Devil Man!
7-9 years, but that's pushing it.
10+ years because I'm not very fussy
20+ years. I'll date anything you put in front of me
40+ years. I am a filthy pervert 

My last boyfriend was 3 years older, so age isnt that much of a problem. 4-5 years would be my limit, ish.
It all changes once you get past teenage years, though. Age dosn't become an issue.