Do I have the right to complain about my situation?

So my sister and I recently moved with roommates, a friend of my step-sisters to babysit for 2 years. Now they paid for our tickets and set our room. We don't have to pay for rent either. They desperately needed a babysitter so we both agreed. Our roommates work in the military, given it means they will be busy. However it's taking a toll on me. I have complaints but not sure if I should be feeling this way because we live for free. However they hardly watch their BABY. The most is 6 hours? If lucky half a night. My sister and I sleep with the baby 7 days a night most of the time. They give us the baby when they're home, if they're watching TV they give the baby to us. Despite we aren't working, I believe babysitting is watching over a child/newborn when parents are unable to or not home. They're home. They have days off, the weekends and still they don't take him for a whole day. The baby is not the only problem. House chores I don't mind doing at all. No problem we live in the same house it's understandable. They had a pitbull, he poops in their house more like in his pen which is a 1 and half feet space. He hardly has space to move and maneuver in. She told is deliberately to not clean his poop if he does leave it because she's trying to "teach" him a lesson. The very next day she told us to scrape his poop and scrape the floors. It was her IDEA so fair thing to do is clean up after him. It's their dog not mine. Idk if I'm just complaining too much. Do I even have the right to?

If you agreed to to 'work' for these people then you basically need to do what they need doing when they need it done. It's their business how they bring up their child and if they require that you guys look after him whenever, then so be it. Whether they're failing at parenthood is another thing altogether and it's a matter of personal opinion, but rest assured, there's plenty of people out there who will agree with you. If you believe about babysitting in the traditional sense, then you're probably in the wrong place because your values differ from theirs and your sense of what's right and wrong is starting to kick in. If you don't believe in what you are doing, and are basically forced to do, then don't do it. You're correct, the dog is theirs, and theirs alone, to clean up after particularly when they make the decisions about it's welfare. Yes, you do have the right to complain but you need to look at your initial 'agreement' to work for them. These people need to understand that for you and your sister to be successful at 'babysitting' their child, you need to be happy to be able to achieve it. Going by your post, their child is basically your responsibility but you also have the right to leave if the situation becomes untenable for you and your standards start to grate against theirs.

That is true, I came in not knowing their ways of method or their values and assume that they're babysitting term would have been same as mine. And communication between the parents and my sister are terrible but I believe that is both to blame because being an introverted person and speaking out for me is difficult. But as a parent they should tell us how things work around the house and how to raise him. They do none of that until we make a mistake. However I usually don't like arguing and just go with it. Thank you for your unbiased response it is very much appreciated :)