Where did these come from...?

A few months ago I started swimming again to get ready for scuba diving this summer, which isn't happening due to TMJ. Oh yes, thank you mother for that gem of a medical condition, but I digress...

So anywho, I started swimming at a gym near my work, which means swim bag usually comes with me to work so that I could swim before or after, depending on my mood....

Well on one gem of a Tuesday, I spent the morning visiting my friend the Bartender, helping him declutter his living room and having some lunch; then, I had to go to the courthouse so I parked my car in one of those garages where they take your keys from you and drive your car into the underworld. Since I didn't have time to go swimming that day I left the bag in my car. The next day, I brought my bag to work and went swimming then went home. My bag was in all four places. (Bartender's, Garage, Work, Gym) No more, no less.

At home, as I was emptying my swim bag of wet belongings, towels, flipflops, swimsuit, goggles, I pull out,... wait for it,... wait for it...
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a pair of men's underwear.

As I stood there holding up a pair of underwear clearly not mine, I was at first a little shocked. Maybe I'm looking at this wrong. Maybe it's a shrug... but when I clearly realized that I do not have any blue cotton shrugs, I debated a few things.

One, should I smell them in that bizarre waft the smell over to you with your hand technique I learned in chemistry (As in are they clean, and no I didn't)?
Two, how did these get here?
Three, to whom do these belong?
Four, where did they come from?
Five, what do I do with them?

I'll let you ponder those questions for a moment.
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So since I wasn't going to take a chance with discovering whether or not the underwear were used, I tossed them into the trashcan and began thinking on the other questions.

Seriously, how did these get here.
I texted Bartender and was like, look I know you like to play jokes, did you put these in my bag? His answer, no. He's pretty forthcoming and honest, and I seriously doubt he could have fit in the size medium. I'm going with, not his.
Then I thought, I was really annoying at the garage, I kept forgetting things for court in my car. So maybe they put them in there, but then WHERE DID THEY COME FROM, I don't think people just have extra pairs of underwear around at work... As I gagged I thought, maybe work!
But that's a twisted sort of prank to play on the new girl, so I'm thinking, not so much, and I'm not about to walk around the office going, excuse me, did you put a pair of your underthings into my bag?
And then I thought well maybe my friend, Mr. SilverGym man was playing a prank on me, but I couldn't figure out how to justify him sneaking into the locker room without women seeing him, and slipping them into my locker.

So the great case of the underwear remains... where did they come from? who knows... to whom do they belong? I'm unsure... how did they get there? Pretty sure someone unzipped my bag and slid them in, but when I dont know...

But I do know one thing, from now on I'm keeping my swim bag locked and one eye to the horizon for men wearing blue jockey briefs.