<human>: Provide a brief overview of the text.

Here's the situation: My fiance and I live 30 miles apart. We have no joint bank account. I left my debit card and checkbook in the other town, and he is away and unreachable until this afternoon. I went antique shopping with 10 bucks in my pocket, figuring I wouldn't want to buy anything more than that anyway.

I found the perfect birthday present for him, and it wound up being 40 bucks. He's comfortable with me using his account and I've taken his debit card to get groceries more than once. I thought my checkbook was in the car, but it wound up being his. I somehow got it in my head that it was totally fine for me to use it anyway, as long as I paid him back.

I explain the situation with the shopkeeper, who said it should be okay as long as I can sign for him. I signed the check in my own name, he compared it with my driver's license and wrote my phone number on the check's memo field, and I went on my merry way only to realize that he meant I needed to be authorized with the bank. 

So, Reddit, how much of a dumbass am I? If we call his bank and explain, will the check go through and everything be okay? I almost wish I'd driven the hour round trip to go get my own damn card.
<bot>: I signed my fiance's check in my own name, but I'm not on file as an authorized user. He won't care, but the bank probably will.