<human>: Yesterday at work I saw a dude pissing all over our unloading dock. I work in the produce department of a large grocery store and we compost lots of material at the end of the night. As we were heading out last night, there was a dude peeing all over the stairs out back. I told him to leave immediately, and he walked away pissing before getting in his car and sitting in a no-parking zone, watching me and a male coworker take out the compost.

I was really fucking upset about this. A large part of it was that it had been a really shitty day overall - lots of awful customers, really busy, etc - but I also just felt generally really uncomfortable about seeing that happen in my workplace. I talked to the manager on shift about what we could do about the guy, because we got his license plate number and car model, and he said, "Well, we could hypothetically call the cops about public indecency with the peeing, but..." And he held his hands up and shrugged as if that wasn't a real option. I didn't pursue it.

This morning I tried to tell my department manager the story and I got halfway through before he burst out laughing and saying he'd done that a lot before at a store near his house. He even mock-yelled at me when I said I'd told him to leave, saying, "Oh, c'mon, you gotta at least let him finish, jeez!" I ended up just walking away from the conversation.

It is unreasonable for me to be this upset/freaked out about this? I really just don't know what to do, haha. Everyone else in my department is a guy, and we have no female managers at the store, so I can't tell if I'm overreacting, if this is just a thing guys do, or if management isn't taking it seriously.

Can you summarize the given text in a few sentences?
<bot>: Caught a dude pissing right outside the back door of my store, pretty shaken up about it, nobody else seems to give a shit.