i think it's entirely feasible that they could've met at some kind of random event? i think especially after eclipse and maybe chronicle, he was being sent off to all sorts of premieres and other hollywood things and the glee cast was basically everywhere around then so they could've run into each other a few times? he would definitely do that for her though! he doesn't do comedy often and would've been excited about the idea of getting to work with someone on a sitcom (i guess glee isn't really a sitcom, but you know)