Reborn, I Put My Stepsister and the Scumbag on the Trending List

Looking for a Book!

A novel set on the filming set of a horror movie. In one of the scenarios, the female lead starts out sitting on the male lead's lap in a car, playing a couple with him. I think she was originally working in an infinite-flow scenario as part of some other type of System, but I can't find the book anymore. Please help!!