Rant* Brother in law

So my brother in law and sister live at my parents along with their baby for now. Am I crazy for thinking that he shouldn’t be laying down on the couch in the living room when everyone’s hanging out in the house. I can’t imagine doing that at my own mother in laws house and I’ve been with her son for 11 years. He’s so comfortable just laying whenever on the couches. I’ve even seen him take off his shoes and socks and just sit on the couch with his legs up on it bare feet like that and he doesn’t care who sees him laying down or anything like that he just won’t sit up. I blame my sister too for not telling him to sit properly. I understand she lays down sometimes but that’s her own parents house. It doesn’t help that my pregnancy hormones get me really pissed at shit. I just feel like I’m well mannered and I don’t like seeing shit like that.