Paying for babysitting among siblings


So we went to a party the other night. I wasn’t planning on drinking but my boyfriend said he offered to pay his son if he watched the baby. His son is 12. It was a close family party maybe 20 of us. 10 of which where kids. His son told me about their deal and I told him I’d double it if it meant I could just sit down. I worked a 10 hour shift before this and didn’t even care about drinking I’d pay anyone who would keep an eye on my son so I could put my butt in a chair and not get every five seconds. Well about an hour after this conversation I go in the living room for something and I find the 12 year old asleep on the couch. No baby. Found him safely with the other kids. For the rest of the party I was the one getting up every time my son went to touch something he wasn’t suppose to, or every time he wanted something off the table, he every time I pulled on my shirt and wanted me to go somewhere with him. Which I’m fine with he’s my son hes 19 months btw. Personally I woulda stopped like 2 beers ago If I new I’d be chasing a baby all over the house. It was fine though, the 12 year old isn’t in trouble, don’t think anyone said anything to him about it. Today I got home from another 10 hour shift and my boyfriend asked if I was stilling running errands if I could stop and get cash so we could pay his son. So here’s the timeline we got to the party at 11, I found the son asleep around 12:30, we left at 3:30. So I’ll admit he watched him for about an hour an hour and a half. My boyfriend said he’d pay him 25 if he watched the baby till we got home, so me doubling that would make 50. I personally don’t feel we owe him 50 dollars. I’m not against paying him but I say the original 20/25. My boyfriend says that’s not fair. What do y’all think