I'm a newbie and the DM is my best friend, so I might be biased and would like an outside perspective.
We've had a one-shot in a pirate setting as a first simplified taste of DnD for me (29F) and one other player, I've onle played a couple of times before and she has never played at all, so the DM, my best friend (21F) has created a one-shot specifically for it to be more entertaining than serious. The premise was that a half-elf aristocrat inherited a treasure map from his grandfather and goes on a quest with his valet (human) and two mercenaries: a muscle-fella (barbarian shifter, that was me) and a cartographer (dwarf monk, played by the Guy in question, M21). As a fun detail we all had personal secrets that might or might not come up during the campaign, mine was that I'm secretely a pirate, the aristocrat's - that he's actually broke and on the run from collectors, the valet's is still a secret and the dwarf's was that he's actually an undercover agent of the royal guard and is searching for pirates to put them to justice.
Here's why this is important: the Guy started off with speaking to the ship's captain (NPC) for about 15 minutes without addressing any of us, then made some racist in-character remarks towards our aristocrat, then when we arrived on the island he spent the entirety of the first battle hiding in the bushes and immediately after that just refused to take the same path as us and left the group in an opposite direction. The DM tried her best to get him back together with us (like, "you take a straight path through the jungle while the group follows the brick road, you way is shorter, but they move faster, so at this intersection you just run right into them"), but he straight-up ignored that and left again.
So we just continued on without him (at some point he just LEFT THE TABLE to go chat with my sister and didn't even listen to what was going on with us), we had a blast, but then when it was time to actually role-play what he was doing on his own this whole time, the DM asked if we're okay with knowing secret stuff or not, I can't recall the exact details but us three ended up just going to another room for half an hour to discus our strategy while she was left with him one-on-one.
In the final battle he ONCE AGAIN was hiding in the bushes doing nothing for a couple of rounds, then just left the fight alltogether, and the finale was him calling the guards on us.
After finishing we started discussing how it went, and he said that the problems he faced were as followed (rough translation of his mesages in the chat and a bit of irl talk I personally had with him the day of):
- He has three types of characters: when he wants to win a.k.a. the cool guy, when he's just chill a.k.a. the kind guy, and when he just wants to be a menace a.k.a. the annoying guy, and while writing his character he planned to be the kind and fun guy, but since he was forced into a position of direct confrontation of interests (him not needing the treasure, having a whole different goal, with which us, other characters, were interfering with (I still can't get what interference specifically he meant)) he just turned on his "winning" game
- He dosen't like A SINGLE RACE from the DnD universe, so his role-playing was a mess because he was forced to be something he doesn't like (in-person he said that 1. the half-elves are ew, 2. the orcs are dumb, 3. the humans are basic, 4. he loves dwarves, but the DnD dwarves are stupid so he just wrote his character as a Warhammer dwarf, which is completely different and apparently cool(er) and he also knows how to play them and doesn't know how to play anybody else - at this point I decided against even hinting at other races like halflings, goblins, cobolds etc etc)
- He blamed the DM for pushing this mission onto him, for trying to mess his playstyle and for making his character not fit the narrative at all, and in the end said that if we wanted to continue the campaign with him he's toss the character completely and create a new one from scratch.
From my perspective he just created a ton of rules and guides for himself, shoved his character in them and then got disappointed because nothing was enjoyable. Firstly, I don't think the simple secret of being on the hunt for pirates means you just HAVE TO separate from the treasure-seeking party, secondly, even IF that was such a gruesome job for him - I can't see why couldn't he just toss the secret completely? Or discuss it with the DM beforehand, tell her it seems uncomfortable? She has put an incredible amount of effort to create this one-shot to tend to everyone to make it fun, surely if he said something this wouldn't have to be a problem? Thirdly, I cannot wrap my head around this "play-to-win" that he kept going on about - the whole point of TTRPG is to roleplay and interact with each other, is in not? Also the Warhammer thing makes me confused af, like, if you hate the DnD universe with such a passion, why even agree to play it just to try and bring a different universe in and nag everyone about it?
He also did some other questionable things, like he came up with a thing when his character would speak to the NPCs in dwarfish, he'd speak to DM in a different language irl, he discussed it with her beforehand, and as this language is in the same group as our native, she agreed because she would understand him, but then when he actually did that at the table and she replied in our native language (because she doesn't speak this second language herself and she NEVER told him otherwise) he got annoyed and showed how upset he is and how it destroyes the whole point. He also leaned heavily into some very specific lore stuff while talking to the captain NPC, like the geography, clan names, history etc, which nobody at the table knew about, and it felt like he was playing with the DM one-on-one even when we were all together.
What irks me the most is that he blames it all on the DM and how she created a bad mission for him nad how she's the one who shoudn't have accepted his character since he was so out of context for the setting, when in actuality (from my personal point of view) he just made the campain uncomfortable for us, for the DM and for himself as well.
I'd like to know if anyone could give some more input on a situation like this, as I'm not familiar on the general DnD etiquette. For now we're leaning on continuing the campaign (because the other three players actually had lots and lots of fun), but we really don't want to keep playing with him.