[ Oh no. Now he finds this guy kind of endearing --

No! He's being the mature and responsible one here! Never mind that this guy is probably older than him. Or maybe it just seems that way because of the size difference.

He forces his expression into something neutral, not wanting to give away his intrusive thought. ]

Well ... you ... don't have to tell them the whole truth. It's enough you're not just walking away leaving them to deal with it. Maybe ... say it's an accident. Let them know you have no money. You could do a little work for them for a bit to make up for it or something.