Got company. $100 missing. Here's what I've done.

[wet work]

I was in a similar situation about this time last year. My gf's little brother(15) comes to stay with us a couple times a year around school vacations. When he left there was $50 missing. I called him up and told him I was extremely disappointed and that if he ever stole from me again I would break his fingers. I also told him if he needed money he could just ask. We're already pretty generous to him. He apologized. A few weeks ago when he was here I had him rake the leaves and load my truck for the dump.

I think he's just in the rebellious teen phase and he's been in some other trouble as well, so I just chalked it up to that. And he's always been a great kid otherwise.