I had a supervisor at a lumber yard that was a grade-A asshole. He was my age - we were both 26 at the time. We were only stocking shelves. He could be amicable, but conversation usually veered towards something strange. He'd say stuff like "hey, f****t" to me, almost daily. I had varying approaches towards 'keeping it real' with him - telling him to fuck off, telling him the way he acts is a waste of our time, ignoring him. He'd ask me which employees I'd rather sleep with, and include underage girls. I would tell him how gross that was, and he'd say "just answer hypothetically".
He wouldn't talk to you or greet you at the start of the shift, and just stare around with very wide eyes. He'd usually drink 3-4 energy drinks over the course of the shift. Once first break hit, he'd insist we all take break out in the smoke shed. He'd have his smoke, and tell us all about Joe Rogan episodes, because he said he'd watched them all. At that point in time, I knew that Joe Rogan had a podcast but didn't really know about the content, and didn't really care. This guy wanted to talk about sasquatches, aliens at Area 51 and "ego death" on psychedelics. I'd engage for a bit, but I found him arrogant in how he approached the topics. He didn't really want to discuss them, he wanted to tell us about them.
He dated a girl on our team - he'd always tell me that women liked being shoved against the wall without telling them it was coming. The girl he was dating seemed shy and withdrawn.
With regular work stuff, he'd withhold information, like how to print off price-tags. Buddy, we're adults - we can make this more efficient if you're not the price-tag nazi. At one point, he had me training a 15 year old kid on sticking stickers on different sales items - some 75%, some 50%, some 25%. I started with the 75% ones. He came over and questioned why I was starting with those ones. I explained that I could start at any set, and it wouldn't matter. He kept rebutting me. I threw all the papers up in the air, and looked him in the eyes and said "it sounds like you want to do it", and walked off. He came blabbering after me and I can't recall if he apologized. Regardless, waste of fucking time.
At some point, I transferred off the team. Dealing with him was a complete waste of my time and energy. They hired a 17 year old kid for the restocking team - he was actually quite smart and had enough roofing experience that he could answer customer questions on it very well. Of course, the supervisor proceeded to treat him like shit. He'd come and tell me about it, because I related and could take the heat off him a bit.
Eventually, this kid saw the supervisor having sex in a spare office with a cashier (different girl from the one he was dating) after-hours. This event was the straw that broke the camel's back. Me and the 17 year old dude went to HR with our 'findings'. I had all of my 'backup' info that I had already casually told managers about, and they didn't really seem to care. Him actively fucking around on shift got him fired. I feel like management should have paid enough attention to understand that he was wasting their time months previously, but they were a bunch of morons. I ended up quitting a few weeks after he got fired.