<human>: Can you summarize the given text in a few sentences?

I'm 22. I have a half little brother (my dad cheated on my mom and had him). The kid is like 8. 

My dad gets him every other weekend...but he's navy so he's gone to work one weekend a month. 

Well on those weekends...I wake up in the morning to find myself home alone with the kid. I can't just leave him home b/c he's not very mature and will harm the pets or get into something. 

So I end up having to cancel my plans and stay home. 

I do live with them while I finish school..but I think its really rude to just assume I will watch the kid.  I would rather them ask and make sure I don't have plans than to just wake up and find out im babysitting. No text, no note, no indication of when he will be back. 
   
Do you think this is something I just need to deal with due to living at home...or am I within my "rights" to demand notice. I don't mind watching him...but I hate having to cancel my plans to do it. Theres been times I have work or school and this has happen.  I've said something about it and he still does it
<bot>: Always wake up to find I'm babysitting. No one asked me before they left...just leave the kid with me.