Complex sentence: Mike reveals that Billy's debt is only eight hundred dollars and agrees to forgive the debt if Margaret accompanies him to a high-stakes poker game as his girlfriend, using her to help spot the tell of another gambler (Jay).
Split into simpler sentences: Mike reveals that Billy's debt is only eight hundred dollars. He is willing to forgive the debt if Margaret accompanies him to a high-stakes poker game as his girlfriend, using her to help spot the tell of another gambler (Jay).