Is it normal having to babysit a total brat for free stuff ?feeling used

My brother and I have to babysit this total brat all the time.It is really ruining my social life. I can barely study because we have to watch this stupid kid.I am a teenager and this is so unfair. He is always walking in on us when we are having sex with our dates.

His mom is never home and we always have to be with the brat. He doesn't know how to do stuff that we are good at and we both end up arguing with him.My mom told me to deal with it because we are getting free food and everything. We also have to pick up the house all the time.Sometimes I can bully him into cleaning, but his mom figures out he did it all by himself.

He is 7 and has a nicer phone than my mom. Sometimes I take it off of him because I can and he gets really pissed. I tattle on him a lot and his mom always believes me, but he gets me back.He told on us both for having a huge party and locking him in the laundryroom.

My brother lied and told his mom he did something bad so she shipped him off to his dads for a week, but he is back. How do I get rid of him permanently? Also his relatives call and visit and don't like how we act? We have both tried to tell them our point of view but they don't seem to believe us? I do feel a tiny bit bad for the kid because his mom never spends anytime with him.She is too busy going to the bar.