April Fool's Day

This morning I told Addie and Ben that today is April Fool's Day, and it's a day to play tricks and make jokes on people. I told Addie that when Muddy got to the house that she should tell her "I fell down the stairs and got hurt." Once Muddy responded, Addie should say "April Fool's!" Ben was supposed to tell her "I pooped on the floor." (I know, classy, right?!) When Muddy came in the house about 10 minutes later, I reminded them to play their trick on her. They bolted into the foyer and Muddy could barely get in the door before Addie said:
"Muddy, I fell down the stairs and got a big booboo" of course she's saying this with a HUGE smile on her face. Muddy looked stunned and said "what?" Addie repeated herself, "I fell down the stair and got a big booboo" SMILING hardcore. I had to to turn away to stop from laughing. Addie's body language and attitude didn't match what she was saying and Muddy looked equally confused. Then Addie blurts out "JOKE!" and starts cracking up. I said "April Fool's." Then Addie got sad, because she realized she said the wrong thing. So Muddy had to play up the surprise and trickery.
Ben then tells her that he pooped on the floor. And then said something like "Aprna bulls" or something like that.
We have to think of something tricky to say to Brian when he gets home. I'm thinking they'll be faking an injury with gauze-wrapped arms or something...