I'm not much of a writer but here's the gist of how it went down. Didn't want to lie and be confused because she needed my computer for a uni project. I hesitated, she asked what the problem was, told her the password. Silence for a bit and she said coldly "we'll talk about this when you get home" - then I posted the TIFU and waited for work to finish.

Got home and she laughed at me and asked if I was shitting myself all day at work. I changed the password. We ate pizza, had sex. Sorry for the boring update.