World is upside down right now

[othstr]

Question, I will need to discuss this with IC also, just wanted to get some more input.

H works a job that he does installations that are scheduled for him. He finds out his schedule the Thursday before the week. He asked me if he ever doesn't have a day scheduled could he take S for the day instead of sending him to the sitter. I said yes, as long as he told me the previous week so that I could let the sitter know. She gets paid by the day, so she is counting on the money that he is there. She already knows the days that I won't be sending him because of my schedule. So, he just sent me a text asking if he could have S because he doesn't have anything scheduled tomorrow. I didn't respond, was giving it time, and trying to figure out what I wanted to do/say. Thankfully, he said nevermind, they were able to find a job for him. If I would have said yes, let the sitter know, then I would have had to take it back and tell her that he is coming. It's hard because he only gets paid when he has a job, and I get money when he has money... He only takes him when it is convenient for him, and he works out of town a lot, so it's only on weekends. I'm not holding S against him, but I don't want him to think that doing everything last minute, when it's convenient is ok. Which also means that if he takes him tomorrow, he won't see him over the weekend, because for him, once a week is plently...

So, my question is, do I let him take him last minute and mess up the schedule with the reliable sitter, or tell him again, this needs to be figured out the week before and whatever we decide on stays?