I think that it just depends on the relationship, what mindset you have and if you're open to the age gap.
I know of people who are 15 years apart and married. It's just about maturity and whether or not you care enough for the person to accept the difference in age.
I know that right now, some people see it as weird, or unacceptable, but I think that love conquers all, and if it's love, then who are we to judge?
I know that if I were in a situation like that, I would pay more attention to their personality and maturity, rather than age.
I know this about age, but what do you think about height differences in couples?
I have friends who will only date a guy if he's taller than them. My grandparents, on the other hand, are completely opposite, my grandma is way taller than my grandpa, and I think it's so cute.