I need help with my fanfic about niall and harry.

I wanted them to fall for girls that are younger then they are. The girls were originally 14. I wanted a story that was different than others. No eating disorders, pregnancies, or being abused. But I feel it might be a bit unrealistic. Idk if I should make the girls a little older like..16 maybe or make the boys younger. Do you think this could be a good fanfic.?? The whole point is "age is just a number."