Warning: this story is gross.
I am orally independent. If you ever need top secret information from me, forget electric shock or bamboo under the nails…threaten to stick someone else’s toothbrush in my mouth. Maybe this distaste for other people’s visible saliva comes from sharing beverages with younger siblings and cousins who were always phlegmy with a cold or too young to understand not to backwash. The communal root beer was always milky by the time it got to me so I would often pass. Likely it was exacerbated by dating not one but two gentlemen who suffered from an over active saliva gland. The goodnight kiss was always a risk. Will it be pleasant or will my mouth be unexpectedly filled with a spurt of hot thick spit? 
Cut to last night. My sister is practicing with one of her bands and this particular band has a stuffy moustachioed trombonist. He comes through the door without so much as an hello. He brings a bottle of wine and you can tell his head is already swimming with music. He heads straight for the basement in his hipster shirt a little too tight. He’s actually a bit adorable in his socially awkward way, my sister and I think. My brother in law has no time for him. About an hour into their rehearsal he thumps up the stairs with his trombone and heads straight for the sink where I am washing dishes. He pulls out his spitty valves, shakes them over the clean dishes then rinses them over the violated pots. I am too stunned with a gag reflex to stop him the first time. When he reaches for the next valve to rinse I almost shout, “clean dishes!” And I drain the soapy dish water on the other side of the sink and offer it up to him while l lean back with a wince. He looks at me a little astonished and simply says, “okaaaaaay…”, offended that his spit of brilliance would be a problem. He rinses the next valve and then humps his way down the stairs again. 
I have to lean over the sink and steady myself, trying not to vomit. You can imagine the depth of my repulsion, given my history. I quickly scrub out the sinks and wash all the dishes over again with water so hot it turns my skin red. And while I sanitize I have a lengthily debate with myself. Even if he was playing with Duke Ellington he has no right to dump his spit all over my dishes. Doesn’t he have any sense of hygiene?! How can I be angry with someone so oblivious? However…he certainly doesn’t mean any harm. Spit is natural. why is it I can French kiss but I can’t share a water bottle? This is all a cultural thing. I mean, you walk down Powell Street and old men will not only hork a half a cup of spit onto the sidewalk, they’ll shoot snot out of their nose with the velocity and accuracy of a pea shooter. Maybe I am in denial that I am an animal? Maybe the trombonist is a genius? This must be. He’s so preoccupied with his inner brilliant world he doesn’t really have time to worry about my petty niceties. Or maybe he’s very highly functioning and on the spectrum in a way I should be sensitive about?
Or maybe – just maybe – that trombonist is a slob. Maybe his parents never taught him about shielding the world from having unwanted contact with his sundry bodily fluids?! Yeah, that’s it. blame his mother.
It is the next day now and I am using the toaster for every meal because I cannot bring myself to use the pots, despite the fact I scrubbed them surgery ready the night before. When I get home from work, my brother in law is at the BBQ, and I thank God for a meal without cookware. Are we giving assholes all sorts of room for their shoddy behaviour with our political correctness or are we becoming more compassionate? I honestly don’t know. But I do know that I’m still not sharing my toothbrush with anybody.
Ick! Your story brings back memories of a kid in my high school band (the band director’s son, in fact) who played trumpet in the chair next to me. His parents had taught him not to empty his spit valves on the floor at home, so he used to empty them into his palm and then wipe his palm on his pants. Eww! He would do that even when he was at school where the floor was gross anyway and who would care. I’ve always emptied my spit on a rug where it soaks in and doesn’t leave any visible mark. But now that I’m in a brass quintet and we rehears in a church with a nice carpet on the floor, I’ve learned a more civil technique from my fellow musicians. I grab a stack of paper towels and put them on the floor and empty my spit onto them, then throw them away after we’re done. At home I now use a rag. Saves my nice Persian rug.