For me personally, age is just a number. If you truly are in love with the person, then there's no stopping you because you cannot control who you fall in love with.
I don't think there's anything for guys to be with girls who are older than them or girls to be with guys younger than them. I also don't have a problem with girls who are with men who are much older than that.
For me, if a guy came off as mature enough and attracted me (immaturity at any age puts me off), then maybe two years younger is okay. I would not want to go for more younger than that because then I would feel like I was with a child.
Personally, I am not comfortable with dating someone 10 years older than me, so I don't think love would happen. I don't think I would approach someone that much older than me. For me 5 years older than my age is as big of age gap as I am comfortable with. Sometimes too big of an age gap makes the relationship kind of like being with an older brother or father. They have experience, so they keep giving advice all the time. At least that's what I've observed.
I'm pretty openminded about everything though, and I respect people's feelings. You can fall love with someone younger than you or older than whether you are a male or female. I do think there are some limits though. Like for example, a girl who's 20 should not be with a boy who's 13 because the boy is not mature enough to make his own decisions. It's morally wrong to pursue anything like that. Although, if the boy is 20 and the girl is 27, it's fine because the boy is older and can think for himself. The age difference is the same, but the level of maturity and life experience is different. The same thing goes for girls who like older men. If the girl is 13, then a man of 23 should not pursue a relationship with her because of the same moral factor I stated.
Overall though, I don't have a problem with people who are really in love with someone much older or a little younger than they are. Provided you really love them and there's no moral issue.