They can have totally met through some school thing or another like class crossover might be a bit sparse just given the timeline of ages here!! But like there's plenty of chances to meet by chance in a lunchroom or something. ... And she's a flirt monstrosity so she easily could have been a little coy and teasing with him prior to actually meeting his girlfriend (or before they started dating depending on how long that's gone ??? shrug) or... something.

But yes I want this it's so suited.