It. Is. Disgusting. multimaster tool
If I am sitting near you and you whip out a brush or comb and have at yourself, you immediately shower me with your head detritus, including but not limited to strands of your hair and flaky dead pieces of your scalp. This may come as a great shock to you, but I don't enjoy this experience. It makes me vomit in my mouth and leads me to homicidal thoughts.
Similarly, if I am sitting anywhere in your general vicinity and you produce a nail clipper or nail file and commence making parts of your nails disappear, guess what? Those disappearing parts go somewhere - yes, that's right, all over me! Your impromptu manicure causes great chunks of severed fingernail to fly madly about, hitting all in their path, and a thick cloud of filed nail dust to descend like the poisonous gas it is.
Next you'll be crapping on the seat and flinging that at my head.
There's this thing in your house (presumably) called a bathroom. Use that to conduct matters of personal hygiene in, and spare your fellow travellers on the number 57 West Maribyrnong tram* the most basic of common courtesies in so doing.
In all seriousness, I am repeatedly driven to energetically wonder...what the fuck is wrong with you?
* not my actual tram line...perhaps I don't even catch a tram... I'm not telling you sears credit card
either way, in case you try to travel with me whilst pooing on my head.