I was a bridesmaid in a wedding where the bride's best friend decided to have cold feet about walking down the aisle right before we were supposed to go in and she refused,
she had form for attention seeking behaviour so we just ignored her and went in without her.
(the bride was entering from a different area so she didn't know about it until later)
Granted it probably wasn't the nicest thing to do just leaving her, but the other bridesmaid and I didn't really get on very well with her and we just couldn't be asked with the drama.
The Bridesmaid never came into the ceremony and her 5 year old who was also in the wedding was just left to be looked after by the mother of the bride.
It turned out the wedding planner had put her into a side room.
When I and the other bridesmaid went in to talk to her after the ceremony she just sat there staring at the floor and wouldn't talk to us.
So we just left her to it.
She didn't even come out for the wedding breakfast, again her 5 year old was left to be looked after and entertained by everyone else at their table.
Several hours after the ceremony the bridesmaid had apparently been sat alone in the room the whole time crying and talking to someone on her phone.
A mutual friend commented and we decided to go and say something to her, mainly about the fact that everyone was looking after her child.
She was sat talking on her phone, my friend said: "do you know everyone is having to take it in turns to look after [your child]?"
she then dramatically demanded the child be brought to her, so we did just that, and she took the child and just left without saying a word.
Two and a half, maybe three hours later she was suddenly back, changed out of her bridesmaid dress with a fresh face of makeup and acting as if none of it happened, it was so strange, she proceeded to act completely normal for the rest of the night and we all just thought she was a dick, I'm pretty sure the other bridesmaid did say something to her but she just said she was "under a lot of stress" and nothing else.
She checked out of the hotel very early the next morning before anyone saw her.
She sent the bride a text message apologising for what she did, she said she had "a lot going on and would explain everything another time", she wished her a good honeymoon and then never spoke to her again... Literally.
The bride spent years trying to get back in contact with her, contacting her family and other friends but she received nothing but silence back.
They had been best friends for 16 years, she was like family to her child and the bridesmaid messed up and then just ignored her forever.
Eventually, she gave up and just left it but she was absolutely devastated and tbh I think she is still upset about losing her friend and not knowing why.
It's been 9 years and no one has heard from her since the wedding.