When a girl has a Blue Waffle and gets wet, then that liquid tends to have a different color than normal fluid, it's turns a blue-red color which is called Blueberry Jam.
Girl: Uh Uh Uhhhhhhh!!!!!!!
Boy:What The Hell is that!
Girl: It's BlueberryJam
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.