First time posting here, on mobile so please excuse the formatting.

For the last few months, I've been DMing my first long run campaign(2nd ever campaign overall) with 3 long time friends and my partner as my players. In the party there is a (secretly) half vampire druid "Ire", a highlands human monk "Duke", a turned tiefling warlock "Asshole", and an undead kenku fighter "Cuts". I changed the names a bit for ease of writing.

For the most part, everything seemed okay and everyone was having a good bit of fun. Our 4th joined fashionably late (session 2), and caused some fun drama for the party in the next session because of it. Reason being is Asshole was a warlock to the raven queen, and the PC that just joined the party, Cuts, was an undead/ghoulish kenku. Nothing too crazy, but they end up finding out Ire has been hiding they're a (half) vampire and they go off the rails.

Asshole was probably going to leave after the raven queen said that he'd either have to kill them or leave their party, but the player didn't want to give up playing this character just yet and was basically begging me to find a way to keep then with the party... so the best I could think of was that another God saw this and took in Asshole as their own new follower to 'help free them from her grasp' so he could stay with his friends.

Well. This specific moment seemed to cause a huge 180 to the character and player for some reason, unbeknownst to me at the time, and their character, once a human turned tiefling, started to slowly turn back after their God told them in a nutshell to learn how to ask for help and learn self value/respect rather than seeing themselves as just a weapon.

The character didn't like that and didn't want to listen to the God that just helped them out. So what happens? They get their magic taken away temporarily as a punishment so they can take time to self reflect. Don't like that at all either.

Meanwhile, Asshole and Ire got into a fight while both were drunk and decided to just fuck off alone and let Ire fend for themselves. Ire ended up being kidnapped and killed due to having been lured away by a necromancer the party was supposed to be trying to find and the only reason they were able to be brought back is due to the other two party members having befriended an old life cleric from the area that liked Ire despite him being undead.

So, now Asshole blames themselves for Ire's traumatic experience after the party saved them and develops an addiction to alcohol. No biggie just means they lose money easy, right? Wrong. And it just keeps getting worse.

Not only does Asshole apparently not like Cuts, but also doesn't like Duke and only tolerates Ire. He doesn't spend time with the party almost at all. He goes out of his way to do quests alone or with only one person (normally ire). Doesn't help out the other two party members, let alone tries to avoid talking to them at all. Sleeps completely separate from the group wether it be camps when the party is in an inn or vice versa for some reason.

What finally started to get on my nerves was when not only was I getting fed up with Asshole's attitude towards Duke, who's being played by my s/o, but also my other players were getting annoyed or bored of the constant harassment/putting down/shitting on of the character too. It was fine for when Duke actually did screw up once or twice, but for a reason not communicated, they just had absolute distaste in and out of character it felt like for Duke.

I got to the point of being so tired of it that I stopped the campaign and told everyone to review their characters and think about why the character was with the party and approached both the player for Asshole and my s/o about this. My s/o had no clue what the deal was since he was having fun with his character. My friend playing Asshole though had a lot to say and I actually had to have help from my best friend, who was playing Ire, to help address this issue.

To sum up the problems about/with them or that they had: 1. Didn't wanna make a backup character.

1. didnt want to make a new character when I gently told them they can't continue with Asshole character.

2. Didn't see how Asshole character was a problem or what the problem with bullying Duke was. Their response was along the lines of "Well if they act like a clown they're gonna be laughed at"

3. The problem they had with Duke is that my s/o thought he was played 'too silly' and causes too many problems that the party has to deal with and is going to put them into "bad situations".... Side note: Duke had only done 2 questionable things outside of combat which was trying to antagonize a town guard and using a criminal as sacrifice for a Potion.

Duke also didn't hesitate to start fighting when there was a group of aggressive potential enemies that had a knife to 2 members throats and tried to ambush the third the same way. This was apparently an issue with Asshole character because they said that" they should've tried to negotiate with them." The area they were in, let me preface, was what remained of Duke's home temple after a war demolished a good amount of the outside buildings and then half the inside of it. So, he was not in the mindset to "negotiate".

I specifically told everyone figure out what you want to do with your character and make sure they want to be with the party or make a new one that will. I wasn't going to put up with this bullshit with people going off alone, not participating with the rest of the party, or being around even though you basically hate everyone(??).

The player that had been using Asshole left because they didn't want to ask to remove my s/o from the game instead.

We now are preparing a (mostly) new set of characters to continue on in place of the old ones and it's accidentally turned into Monty python and the holy grail and I will never not be happy about the fact that, despite them being a long time friend, they left due to them being a shitty player.

Oh, update to this: they want to DM for a 6 people campaign now and tried asking me and my best friend to join which we politely declined. No way could they handle our silliness.