I went to Fangoria (horror movie convention) by myself as a teen (dad was too cheap to get a ticket). I entered a theater for some obscure horror movie from the 60s.
The theater was nearly empty, so it was very obvious when two guys came in, whispered something to each other, pointed at me. and separated.
This 36 year old obese man with a puca shell necklace and bleached tips sat next to me. He asked me my name and I was polite and just said "hi, I'm 16"
"I'm 36"
Then he followed me out of the theater.
Me., a true crime junkie at the time, was thinking "fuck no I'm staying near the crowds" so I went to the artist alley and talked to a bunch of people while he kept following me. Then I hopped into a crowded showing for a film preview. He got cold feet and finally left me alone.
I wish I had the sense back then to tell the staff about him, bit I was so shaken that I just went home instead.