It's charming you have given this so much thought, but the age gap is relatively small & she is of legal age. It seems fine to me. Given the time of year, I imagine their HS days are nearly over anyway.
"Charlotte sometimes dreams a wall around herself. But it's always with love - So much love it looks like everything else. Charlotte Sometimes - So far away, glass sealed and pretty." - The Cure
I didn't think it was a joke, but I am genuinely shocked that anyone might consider this unsavory. It's only three years' difference between adults. If you end a relationship over this issue, you might come to regret it when you're a few years older and realize how little difference this makes.
Everybody have fun tonight. Everybody Wang Chung tonight.
I've read nothing but part of the OP, but here's the rule:
Divide by 2, plus 7.
Once you're old enough to bone, this golden rule works pretty much all the time.
See, it works.
It's God's math.
The Justice Fighter
XXXX - XwX Xdw XwX sx/so - Neutral Good
"I trust what you are doing though…I just see it a little differently.
I don’t see it as you stepping away from the fire. I see it as the fire directing your course.
No matter how airy or earthy or watery you become... to many of us you will always be...a super nova."
"Behind these gates of seeming warmth sits, loosely chained, a fierce attack dog. Perhaps not crazy, but dangerous"
The age gap doesn't seem that bad. Anyway. Sorry for being the SP who says "do what feels best" but.....
Pick which one you feel the closest connection to and continue. If the age thing is a big deal for you - which I understand - then don't make it "official". Keep your options open. Play the shit by ear until a clear front runner is apparent. Be honest but be true to yourself and your wants.
18 and 21 don't sound so bad on paper. Especially when you are in your golden years looking back on your youth. 30 and 18 or even 30 and 21 sound worse.
But I remember when I was back in college and thought it was strange that people in college were dating high schoolers. It just seemed like a very significant demarcation college/highschool. There was a 22 year old woman I worked with and she was so depressed after breaking up with her pot dealing high school senior boyfriend that she cut off her hair (she was ENTP). I remember thinking "man, what a loser". Perhaps judgemental, but true. I didn't like her to being with so that probably had something to do with it.
But, the older you get the less of a difference those 3 years seem to make.
“If you want to tell people the truth, make them laugh, otherwise they'll kill you.” ― Oscar Wilde