This perhaps is not really seduction but I think it is a good scenario for others since I tried to find something on this subject but couldn't find anything. I feel this is somewhat an 'FR' in terms of improving one's life.

This friend of mine has a history of flaking. You could say he was master flaker about 5-6 years ago and we parted. About 2 years ago I stumbled upon him in a store and we started talking again. We made some plans but I was of course hesitant but decided there was a second chance here. Until recently, there was the occassional flake on his side (1-2 times) but it went way better and we became best friends again.
I say recently because it changed. He has a girlfriend but it is not all good with them. She hits him sometimes and he has to pay for everything. He told me his bank account was drained by 70% since hes has to pay for everything! (WTF?!). Obviously I said to cut the relationship but they 'love' each other. Weird way to show love huh.

We decided to go to the movies about 2 weeks ago, on the morning of the movies he flaked on me. I was really mad about this since he refused to pay back the tickets (I said he had to pay mine as well since HE flaked). He had to go to a birthday or something. Eventually he agreed. I cut him some slack though since I went to the movies with someone else and I said to not pay for mine.

He agreed when I said that he should inform himself when he goes to the movies on the date. Fast forward to tonight since we agreed to see the new Batman vs Superman (Go watch it btw!). 2 hours before the movie starts I get a chat message. "My girlfriend is coming too, she will sit on my lap". I respond with "No dude, I don't want that. You're going to get touchy with each other and I am going with YOU not with HER", good text right? He says: "She's coming anyway". At this point im pretty upset. I feel he has zero respect for me. Not only did he not ask me if she could come, he does not understand that I will be the third weel here.
I didn't really wanna go but tickets were paid and so I went. I arrive and I see him. He's alone. He tells me she decided to stay home. I still feel weird about this so I respond with 'Aha' and I start putting my bike away. I turn around and who is there.
Guess...
Yeah obviously. 'Wow you caaaame?' while they're hugging each other for a minute and kissing. I just stand there in silence. In my head it is going 'fuck that, she probably was waiting somewhere for me to show up'. At this point I didn't wanna go AT ALL, but tickets paid made me go.
SO we go in and sit down in the cinema. I wasn't too pleased but nothing I could do at this point but enjoy the movies. And it happened. I just knew it would be like this. They start getting all over each other making the make out noises while the movie is going on. I couldn't enjoy the movie at this point. I made the decision to get up and just sit somewhere else. This may sound weird but it took me some willpower to actually do that. I went to sit with a guy that was by himself too and we talked after the movie. Great guy.
So, great movie I just did not enjoy the first 5 minutes of it.
Lights come on and I wait for an after credits scene (don't wait since there's none). My friend comes up to me and asks why I went to sit somewhere else. I respond that I couldn't stand the noises they were making and just wanted to enjoy the movies. He just starts laughing, not hard or long but enough to know that he didn't think I was serious. 'Are you jealous?' he asks laughing. I don't respond.
When the credits were done the friend and his gf left before me and he waited at the toilet. I was having a 'fuck off' moment and just walked with the guy I just met to the outside and went home.
I got a text 'Are you serious? You are leaving without me?'. I respond 'Yeah, weird huh. Call me tomorrow. '. He basically blamed me for leaving and sitting somewhere else saying I could have just said it.. Sure thing mate, THINK.
I said he had no respect for me to which he responded that he didn't understand and that his gf was having a hard time that day cos of something and that is why he brought her. I didn't respond.

TLDR Made plans with friend. He said he would bring his girlfriend, did not agree since I knew I'd be the third weel. He still brought her. They nearly messed up my movie experience with them making out, but went to sit elsewhere. He did not understand why I went to sit somewhere else. Felt he had 0 respect for me.

I just had to write this off me tbh. He has no clue what he did wrong. IMO he handled this all wrong. Perhaps I should have explained it all to him but he should just THINK. He MUST have known that I would be the third weel here. I don't really want to be a part of it anymore but he is/was my very best friend. Do you guys have any tips, what to do next? Cut him off completely? I don't feel like losing a friend but I feel this is gonna get way more toxic soon. Thanks :).