Frat house phrase popularized by "The Degenerates" of 4th East ("Beast") Hall. "Cut to the fuck" was the battle cry used during the pathetic interludes and lame attempts at plot development inserted between sex scenes of a porn movie.
After the first couple finished they had a scene where John was talking to his friend in a coffee shop about his relationship with Amy and if his wife would mind. That crap in porn movies is so lame. CUT TO THE FUCK!