Edit: I 100% am having a private conversation with them. Which is what I would have wanted them to do. I can, and do stand up for myself. I was caught off guard and honestly pissed. Didn't want to make everyone uncomfortable at dinner. I realize I could have simply said this or that, but it wouldn't have come out of my mouth very nice. No, my husband didn't volunteer me. It's my sibling.
UPDATE: I realized some of you were right. I needed to tell them ASAP so they can plan actual daycare. I called him lastnight.
I calmly asked him if he really thought I would be watching his baby. He said yes because I was home all the time. I asked him why he didnt ask me first and he said he didnt think he had to. It really pissed me off. I said I have plenty to do and that if there is an emergency I will be there and help, but that I wasn't going to watch the baby everyday. He then got pissed and said they planned for me to and now they have no idea how they will afford childcare. (This baby was planned i should add)
He is upset because he also needs to workout for 2 hours a day after work. He feels now that he wont be able to and that will mess up his mental health. They work from 7:30am-4pm and workout for 2 hours after that.That's around 10 hours I would have this newborn. I said so your having a baby for me to take care of so your lives dont change? You want me to give up my free time, but you wont? We have talked about how happy I am in this moment with free time. He said a child is more important than your hobbies. Which totally set me the rest of the way off. I said mine are, because I had them. Your child is more important than the gym. It's not up to you to decide what I do with my time, and you can workout at home. I said i was sorry and hung up. Now its going to be super awkward but at least they know now.