A party isn't a party without.... (lighthearted)

[WhatInTheWorld76]

Balloons
Cake
Music
Food....

Someone crying. Whatever the age group!

Tequila

Cheese and pickled onions on cocktail sticks

Someone crapping themselves every time a balloon pops!

A corner for me to stand in and hope nobody tries to make conversation. Hello social anxiety.

The "drop and run mum" who cannot get out the venue fast enough!

A mega early arrival, a late comer and someone who doesn't turn up at all because they got their dates mixed up.

Party rings.

Abba! -being sung and danced to badly by your aunties--

Balloons.
Someone's mum/Dad forgetting (probably on purpose) to collect them on time.
Party bags.
Party biscuits.

Cheese & pineapple on sticks.
Mil and SIL not talking to each other & separately making hissed PA complaints to me about the other one, making me long to lock them together in a room until they either talk to each other or kill each other, I don't really care which.
But I think that second one is just my parties.