When MIL comes over she files her nails and her elder sister's nails sitting on my sofa in our carpeted front room. It really grosses me out because I imagine the nail residue going onto my sofa and carpet and I think it's rude. It wouldn't cross my mind to do that in someone else's home - it's a step away from clipping your nails onto someone else's floor but at least with that I suppose you could pick up the clippings!
I haven't said anything to her because she is very sensitive and plays the victim over everything so I try to keep things as light as possible.
Am I being incredibly precious or would this bother you?