Complex sentence: The next day, the newspaper has an item about Finn and Rachel--school reporter Jacob Ben Israel (Josh Sussman) had spotted them on their stakeout--making Quinn furious with Finn, and Finn is already mad about Quinn being at the motel with Sam.
Split into simpler sentences: The next day, the newspaper has an item about Finn and Rachel, who were spotted on their stakeout. Quinn is furious with Finn, and Finn is already mad about seeing Quinn with Sam.