This game is super popular, cheap and I play it all the time for my birthday parties (I am 14) and it's so easy and amazing for everyone.
Thread donuts through a long piece of yarn or string, (one donut for each person) and then hang the sting up (I recommend one wall to another, or on your washing line!) you can adjust the heights of the donuts accordingly.
You have to try and eat the donuts off the string using your mouth only, no hands! Whoever finish eating their donut without using their hands first, wins!
Bonus challenge: Don't lick your lips whilst eating the donuts...