To feel used by family

[reddevil22]

So this week Sat - Thurs I have been staying with and looking after my 2 nephews 4 and 6, my brother and SIL asked if i could travel to see them as its half term and they need help with childcare.
We have done a few fun activities together and I have really enjoyed looking after them. Yesterday my SIL spoke quite rudely to me about something basically treating me like I'm one of her staff. I didn't confront her about it as I didn't want to argue in front of the boys. Later that night my brother made a comment and I told him I didn't like the way SIL spoke to me. He said he doesn't blame her as I have just had a free holiday and had all my meals cooked for me. I said that I have looked after the boys for them so its hardly a free holiday to which he replied so you should you are their aunt.
I feel really hurt I enjoyed spending time with my nephews but now feel like I they didn't want me there to spend quality time with them just to use me.
AIBU to feel so upset about this?

So they see it that you have come your a free holiday and be waited on, when the reality is you have child minded for free and forgone some of your leave.

Tell them this, then tell them it's the last time.

100% solid gold CF’s!

Do NOT be available for free childcare for them again.

Next school holiday when they ask for your help just say ‘Nah, already booked my holiday this year, thanks for offering’. Also, send them a childcare bill. £50 a day seeing as you do cheap family rates.