I once knee on bellied someone who coughed phlegm straight into my open mouth.

I was a new purple belt and at the time and the highest rank overseeing open mat one day a few years ago. We had a guy in his 50s drop in. He was cordial at first and seemed nice enough, but proceeded to only roll with the women, and said no whenever any of the guys asked to roll. I had just noticed this and some red flags were going up when one of our ladies came and told me he had been really rough and she couldn’t tell if he was deliberately groping her in their roll or if it was just incidental, but that it kind of bothered her. I had been rolling myself and hadn’t seen anything but that was all I needed to hear. I looked up just in time to see him grab the chest of the woman he was “rolling” with, she tapped but he wasn’t letting her up, instead acted confused about why she was trying to get away. I was already on my way straight to him. “Hey, let her up. She tapped. What’s up man? I’m Seth. Let’s roll” hahahaha he said “Nah, I’m ok, thanks though” and I chuckled and said “I’m not really asking”. He wasn’t standing up yet, so I shoved him over and squished him. He would tap to pressure, so I’d barely let up, and say “Hey good job let’s go again” and just move to a different position to crush him. I never injured him, I didn’t choke him unconscious, just lots of rude forearm to face, hanging out in kesa or knee on sternum where he could barely breathe. And every time he tapped I’d let up for a second and then just immediately go again. He finally was just laying there too tired to do anything but barely tap. I was not very polite in telling him at that point he was no longer welcome and never would be, and to leave immediately. I’m really glad I was there. But I mostly felt sick it had happened in the first place. I apologized profusely to the two ladies who had the misfortune of rolling with him. And now, I watch brand new open mat drop ins like a hawk for a while and often hand pick their first few rolls if there’s the slightest doubt in my mind. Fortunately, all of our ladies now are no longer white belts would tie a guy like that up into a pretzel without any help.

according to him blue belts cannot ask black belts to roll

Wow on behalf of other ladies... Thanks for swooping in like a hawk on strange guys. There are definitely some creepers out there.

I think partly because our coach doesn't allow drop-ins.

I once tapped to Tiger Balm. My training partner had some bruised ribs (after somebody who looked just like me had kneed him a bit too hard in sparring the previous week). He kept training despite the injury, but had slathered the entire right side of his torso in Tiger Balm, which—if you are unfamiliar with exotic unguents—contains menthol and camphor along with a bunch of fragrant spices. Basically, it smells like someone is trying to bake cookies in a chemistry lab. We were training no gi and my partner caught me in a guillotine choke. I defended by throwing an arm over his shoulder, grabbing the wrist of his choking hand, and—you guessed it—turning my head towards his ribs so I could tuck my chin. That’s when it hit me. Thirty minutes of sweat had turned his ribcage into a noxious pool of weapons-grade chemicals that immediately infiltrated my right eye. (Seriously, the police could probably quell a riot with that stuff.) I started tapping like Samuel Morse. My partner let go and said, “I didn’t think I had that choke… why did you tap?” I cried, “TIGER BALM!” and stumbled toward the bathroom, followed by his peals of laughter. I guess he got revenge for the bruised ribs.

I once tapped to Tiger Balm. My training partner had some bruised ribs (after somebody who looked just like me had kneed him a bit too hard in sparring the previous week). He kept training despite the injury, but had slathered the entire right side of his torso in Tiger Balm, which—if you are unfamiliar with exotic unguents—contains menthol and camphor along with a bunch of fragrant spices. Basically, it smells like someone is trying to bake cookies in a chemistry lab. We were training no gi and my partner caught me in a guillotine choke. I defended by throwing an arm over his shoulder, grabbing the wrist of his choking hand, and—you guessed it—turning my head towards his ribs so I could tuck my chin. That’s when it hit me. Thirty minutes of sweat had turned his ribcage into a noxious pool of weapons-grade chemicals that immediately infiltrated my right eye. (Seriously, the police could probably quell a riot with that stuff.) I started tapping like Samuel Morse. My partner let go and said, “I didn’t think I had that choke… why did you tap?” I cried, “TIGER BALM!” and stumbled toward the bathroom, followed by his peals of laughter. I guess he got revenge for the bruised ribs.