Annoying BIL

Update: a lot of you are saying that I should have more patience with him because he’s a little kid.. I have 5 younger siblings and they’re not nearly as messy as this kid. At his age I was doing my own laundry which is probably why I can’t fathom why he fails to clean up after himself after several conversations about being cleanly and hygienic.

Y’all, I feel so bad for feeling the way I do about my S/O 9 year old brother but holy shit, I can’t handle being around him for more than 20 minutes. 😩 He asks the most obvious questions eg.(“what are you guys eating?” While I’m taking a bite out of my cheeseburger with my McDonald’s cup in hand. Or “what are you doing?” While I’m walking out of the front door, keys in hand and my work uniform on.) he’s literally so DIRTY. I mean leaving shits in the toilet and leaving his messes in the kitchen (he spilled a whole cup of kool-aid on the counter & floor and just walked away from it.) And SO much more. Should I feel bad for being annoyed with him?