Reasons for not paying a babysitter?

I just finished babysitting for 3hrs for a family with 4 kids 18m, 3, 5, & 6. We didn’t talk about payment but my older sister has babysat for them before and I was expecting anywhere from $10-$30. What I got was a happy meal. That’s it.I don’t think I did anything wrong (besides not talking about money before). I kept them entertained, picked up all the stuff they got out, and cleaned the kitchen. I also got bit, head butted, and hit in the ear with a sippy cup so hard that I could only hear buzzing out of it for 30 min.I’m really upset about not getting any money for this and it’s not even really about the money. I can’t figure out why. WHY did they think I shouldn’t be paid? I know we didn’t discuss it but why did they assume it was free? Is that why they asked me to do it because they thought I would do it for free or wasn’t worth paying?The kids had fun and the house was in better condition then when they left and so I don’t know what I possibly could have done wrong and seemed happy with the job I did. They bought the happy meal before they even got home so I’m telling myself it wasn’t my fault and that was their plan all along but I can’t stop thinking it’s my I did something wrong.They’ve never not paid my sister and I just don’t understand. Has anyone else asked someone to babysit expecting it to be free but not telling them? What are your thoughts on the situation? Is it wrong for me to feel angry about it when I never outright asked to be paid a certain amount?I want to ask them why, but I’m too shy and if I was going to confront them it should have been on the moment, not after getting home. It’s just too awkward now but I feel so horrible about the whole thing. Why would they do that? Any thoughts? via /r/Parenting https://ift.tt/2G31W8P