[@Ailyn Evensen]  XL would not fit my hands as well as the regular one.

[@Shoryu Magami] I have a lot of keys, but none of them will help your situation, unfortunately.  Can I interest you in a sarcastic comment instead?

Seriously, though, that's really awful.  Of all the things I've misplaced over the years, I've lost my keys precisely once -- and that wasn't so much lost as "realized I left them on the bench a yard away but behind the door I needed my electric fob to get through".

If all else fails, Ailyn, you could stick it in his mailbox, if that's outside his house and doesn't require a thing to get at.  Or somewhere and then you...um.  Oh right phone is dead.  Well, instead of haring after him, it'd be better to wait at his door.  Or inside, maybe.  Since...y'know, the boyfriend will have a key.