I Say, You Say Louder
It’s like a loud version of tag, but with words. You whisper the word, then the next person yells it louder, and it keeps getting worse until someone is screaming like a mad person.
My friends and I did this with 'unicorns' and the whole class heard it.
I used 'I do believe in fairies' with my sister and it turned into a full-blown war.
Me and my buddy yelled 'penis' so loud my neighbor came out of his house.