I was being facetious, if you don't string them he won't break them and blame you. I was not really insinuating it was your fault the strings broke.
So if he goes to someone else youll get mad and won't string for him any more? Sounds like you want to string his sticks so what's the problem he is just making you happier?
Sund like to me it a younger adult stringing for a younger adult. You want to get paid but don't want to ask for payment. Well you don't have to ask. If you want payment for stringing tell him up front you can't keep doing it for nothing and how much it will cost. I have a few customers that blame me or the strings for their string breaking. I don't mind at all. I tell them I make more that way.
I have the ability to drive people crazy, not sure if I was born with it or I learned it but I'm damn good at it.