The brother (in his early 20s) is troubled with severe anxiety and suspected autism. He lives with his mum and doesn't go out unless a family member takes him out. He's very intelligent and fairly polite and I have nothing against him personality wise.
However, he is extremely messy and lazy with bad hygiene. Now, I know it's not by choice (mostly). But the smell, him not washing his hands after the toilet, not showering, not taking his dirty plates to the kitchen or rubbish to the bin etc drives me absolutely nuts. He makes zero effort to contribute to household chores when staying with us and my boyfriend does him no favours, just acts as his servant as he feels sorry for him.
The brother doesn't often stay with us but when he does it can easily be for 2 weeks or more so it's enough to drive me nuts. He also quite happily sits on our sofa the whole time and plays XBox so I feel like I can't put 'my tv' on. We have our own kids and don't need another, even temporarily.
However it's an extremely sensitive topic to my boyfriend as he feels like his brother has been neglected by their mum - no life skills taught, dysfunctional ways, no positive role models. So he refuses to be strict with him and has to find discreet ways of making him have a shower for example. He feels mortified if I ask him to ask his brother to tidy up. His response is that he is our guest. We have had arguments about this several times.
We are both busy hardworking people with our own mental health issues but my boyfriend doesn't see this as an obstacle as he feels like the visits really make a difference to his brother's wellbeing. And fair enough, of course they do. He has more sensible adults and stability/normality here than at home ever.
I've just heard my partner has invited him to stay again and I'm furious but feel so guilty. I want to say no but never could. I feel like coming up with an excuse why he can't come and stay.
AITA?