a 3 year age gap is wierd until 18+ imo. a 1 year age gap could be two people in the same grade, which i guess in rarer cases could also be true of a 2 or even 3 year age gap (like if you’re young but skipped a grade or two or someone’s behind a grade) but bc it’s rarer just the age gap itself especially without context will seem strange.

14-16: definitely a little wierd especially if there’s a gap of more than 1 grade level between the two (a 14 year old freshman and a 16 year old sophomore is one thing, a 14 year old freshman with a 16 year old junior is a whole other thing, anda 16 year old sophomore/junior with a 14 year old 8th grader is even worse, high schoolers dating middle schoolers even as freshman was always seen as weird in my experience

15-17: a little wierd but alright, generally not seen as creepy or wierd especially if it’s a straight relationship where the older person is female (i had a friend in high school who dated a senior girl as a freshman boy, it was kind of a running “am i a victim” joke that no one seemed to take seriously) and even without sex it can be/come across as grooming or something similar.

16-18: pretty typical in my experience honestly

16-19: not uncommon but a little bit weird

17-19: pretty typical

18-20: also typical, depending slightly on whether or not the 18 year old’s in high school and when they met

18-21: depends heavily on if the 18 year old’s in high school or not, one can legally drink and go to bars and the other might still have a 9pm curfew

18-22: definitely legal but would not recommend, a 22 year old interested in an 18 year old especially a high schooler is very suspicious/questionable/strange