<human>: Give me the gist of the text in a nutshell

Back story - Me and my fiancée have enough money to get by, we aren't struggling for bills or anything, but we are rarely left with any money left over to buy things for ourselves, so she was really excited when her birthday came around to have some money to go shopping together.

Last weekend was her birthday - her 21st no less - and my family, her family and our friends all went out for a meal. She was getting the usual gifts, some jewellery boxes, a few clothes and some plushes as well as cards containing well wishes and occasionally money. Now bear in mind this was a 21st birthday there was a relatively large sum of money here, I didn't count it but I would estimate £150-£200.

As we are all out for a meal, everyone is dressed up nice, and as is always the way with female clothes she has no pockets and therefore nowhere to put the money, so she hands it to me and I put it in my wallet - no problem. This is the start of the FU.

The night goes on and I recall having my wallet at various points through the night, mostly to buy her drinks and other little things with what money I could put aside to spoil her a little on her birthday. The night finishes, everyone says goodbye and I drive myself and a few friends home. We eventually get home, go to bed and talk about what a good day her birthday was. The next morning I get up for university and can't find my wallet  - "no big deal it will be around somewhere in here i'm sure". It's now almost a week later of frantic searching everywhere I can find and calling the restaurant to see if we had left it behind and so-far nothing. Tomorrow was the day we were supposed to go shopping together and I have to tell her that we can't because I lost her birthday money. I lost her 21st birthday money that she was so excited to spend.
<bot>: I lost my wallet containing my fiancée's 21st birthday money that she was so excited to spend and I'm the worlds worst person.