What was the biggest party went wrong moment you've witnessed?

I've posted this story before, but it's too good not to post again:

Birthday party of one of my best friends when we were in college roughly around 2011. This was a house party on a dirt road halfway between civilization and bumfuck nowhere and was full of a ton of people we had known from HS (and a ton that we didn't know). The house was PACKED, you couldn't move without touching three or four people. I would like to say it was controlled chaos when I arrived, but I would be lying: it was simply chaos. So, I find the birthday boy, "John". John greets me with a huge smile, and it is immediately obvious that he's been heavily drinking since before the party started. After a bit he invites everyone into the living room of the house, which could hold maybe 20 of the 50+ people there, and gave a thank you speech on top of a pool table while downing some PBR. He finishes his speech, jumps off, grabs the closest girl he can find and tells her "It's my birthday, you have to make out with me." Amazingly enough, she agrees, and they leave to make out for some amount of time. I make my way into the party to mingle with friends.

Fast forward an hour or two. John has used the "It's my birthday" line about 20 times so far, and it has worked almost every time. However, he can no longer stand. It's time to take John to bed. This is where things get stupid. John's bedroom was upstairs, at the top of which were a couple windows looking into the yard. With the help of a girl I barely knew I carried John up the stairs, and started to turn him around the corner to walk the hall to his bedroom when he stops me. I think he's about to puke, but instead, he screams, "I'M HAVING SO MUCH FUN!" and he rushes forward, slamming his fist through the closest window, and falling on his knees. I am awestruck. There is blood and glass everywhere, and I don't know how bad the cuts on his fist and arm are, but I can guess. Thinking quickly, I yank him onto a nearby couch, sit on his arm, and direct the girl with us to grab a wet washcloth and a sober person, all while John giggles and tries to pull out his phone to take a picture, exclaiming "I showed that bitch window who's boss..."

Someone brings me a cloth, and I spend about 10 min. picking glass out of John's arm, waiting for any sober person to come to my aid. No one does. I tell John to sit tight and run downstairs asking people who's sober. Answer: No one. Not even close.

I reach the front door and another friend, D, rushes in. "Hey D, can you help me a minute, John is bleed-" "Not now man..." D pushes me aside and walks to the other room. Now, I did't hear the first part of his conversation, but I definitely heard the second... "YOU SLEPT WITH MY GIRLFRIEND, THAT'S THE PROBLEM!" were the words I heard before I turned the corner and saw D beating some poor sap's face to a pulp in a corner. I turn and head back upstairs.

I arrive to find John recording the blood coming out of his arm with his video phone and decide to drag him into his room. I provide a bucket, which he immediately pukes into, and then wrap a towel around his hand and wrist. The cuts are not too bad, but they are bleeding all the same. I get him tucked in nice and tight and am just about to leave, when seven fucking people barge into his room, drunken and stupid, asking if he's okay. I try to escort them out, but that idea was shot down the second one of the turned on his electric keyboard and started singing and playing Wonderwall or some shit while John emptied beer and the saliva of 20 women into a bucket.

After about half an hour I am just getting the crowd out of the room when someone bursts in to inform us that a literal brawl has started in the front lawn, as a group of kids from another school had crashed the party and tried to steal some booze. I look out the window and sure enough, there is a brawl going on outside, with at least one kid from the wrestling team brandishing a crowbar he pulled from the back of his truck. I say "fuck it," and kick everyone out as someone calls the police. I ask a trusted female friend to watch the door, and I drive the fuck off.

To put an end to a great story, the "trusted" friend that I left to watch John ended up hooking up with a guy in John's bed...while John was passed out next to them...

TLDR: Friend makes out with 20 women, cuts open his arm and bleeds everywhere, while a fight breaks out, then a brawl, ending in sex on top of a passed out birthday boy.

/r/AskReddit Thread