A childhood belief about speaking

My OLDER (Haha) sister had two friends sleeping over and it was late at night when we rememberd to walk the dogs so we all had to go together so we wouldnt get kidnapped (That was the rull) And so me, her and her two friends were walking the dogs at the park and one of her friends just randomly sai the word "Mojo" (From Austin Powers) And they all started to laugh (And yes, they are all older than me!) And I said, do you guys even know what that is? And they all said yes and I said, okay, then what is it? And my sister was like, we cant tell you! And I explained it to them and they were like, nu'u! And then they asked our sixteen year old sister and she said the same thing and they wouldnt talk to me for the rest of the nigh! XD