The Surprise Jizz Theory (SJT) Is when you close your eyes before you ejaculate, and spin, run, etc. around and when you're done, you open them, and see what you jizzed on. It could be your Carpet, TV, Girlfriend, or even your Cat!
Jack: Dude! I used the SJT yesterday, and it got all over my dog's face. He was pissed!