p.u.s.f.
It’s when your pants feel like they’re about to catch fire because you’re too busy thinking about sex.
I was eating lunch and suddenly I was P. U. S. F. because of a boy in my class.
He said he was P. U. S. F. after seeing his crush in the cafeteria.
I texted my friend ‘I’m P. U. S. F. again’ after seeing a guy in a tight shirt.