Every wedding has at least one them -- guests who just can't seem to keep their sh*t together.

One Redditor recently asked users to share the "most appalling" wedding guest behavior they've ever witnessed. Below are 12 stories that range from mildly embarrassing to straight-up disgraceful. And yes, alcohol is often involved.

2. "The brother of the groom proposed to his significant other."

5. "I was at a wedding maybe five years ago. The bride's family was from northern Canada. During her speech, the groom's mother said, 'I want to thank the trailer folk for coming down.' My mouth hit the ground."

9. "My uncle, who was doubling as the photographer, fell through a wall because he was so drunk. He also loaded all of his film wrong and no pictures came out."