When I was 15, I went back to Judo after a long break. It was fun at first and I made some friends from my high scool. A few months later, a new guy joined our club. He was a black belt, which is common as higher belts often help teach or spar to prepare for competitions.
I won't get into his looks, but there was Something deeply unsettling about him. He had this blank, expressionless face that never changed exept when it would shift into a terrifying smile. Sometimes, the coach would pair the black belts with lower belts. As a young guy and a yellow belt, my absolute nightmare was having to spar with him.
I'll never forget one specific session. We were praticing a technique on the floor, sitting cross-legged. I was positioned directly between his legs while he was 'correcting' my form. He told me to place my foot against the side of his thigh. As soon as I did, he let out this weird, involutary-sounding moan. When I finally managed to execute the move, he looked right at me with a dead stare and, in a low, breathy and genuinely terrifying voice, whispered: 'Ah, you're very strong.'
I didn't have many more interactions with him because I quit the club shortly after for this reason, among others. At the time, I just felt deeply creeped out and wanted to get as far away from him as possible. Even now, at 17, it stands out as one of the most uncomfortable and predatory encounters I've ever had.