No way you should clean after drunken brothers vomiting. Wtf?

Saying all that I don't get it how two adults living with parents only have to keep their rooms clean and one bathroom. Who does the rest? Honestly living rent free and only working part time imho means adult kids take care of all cleaning and other chores like vacuum and dust the whole house etc etc with that many people and pets there is a lot to do! Who does everything? Yard work? Mom?

Take on additional responsibilities around the house and then tell mom that vomit isn't your responsibility. Otherwise she might just see it as you are being freeloader like your brother

Your parents are very much enablers. I really can't Imagine!