Would you tell us a nickname you've given someone (or known someone by), and the story behind that name? [Possibly NSFW]?

Positive or negative. A ‘handle’ given to someone who’s name you didn’t know or didn’t want to use.

We once went to an older man’s house to see about buying some vintage items.
The guy was long winded, and full of himself.
I can deal with that.
But.
Every word he said, he spit.
I was dealing with it until my friend stepped into a sunbeam while conversing with the guy.
All I could see was silver orbs of spit showering my friend. I could not believe my friend as able to stand there and be showered in spit.
The old guy is, was and forever after dubbed by me:
”Mr. Spitty”