In the United States, many states have adopted close-in-age exemptions. These laws, known as "Romeo and Juliet laws", provide that a person can legally have consensual sex with a minor provided that they are not more than a given number of years older, generally four years or less.

But yeah, it'd be weird anyway. I wouldn't do it. Only maybe if they have started dating when one is 15 and the other is 16 or something like that. Even then, at that age 1 year can be a non-negligible age difference.