You, your girlfriend Kelly and your best friend Chris went to the Halloween party at a public venue. As the party progressed, Chris and Kelly exchanged glances with each other, but she also looked at you too. Eventually, the party ended three hours later and you three went to your respective houses.

You couldn't sleep, reeling from the memorable time you'd had. You decided to visit Kelly at her house, but upon your arrival you heard noises coming from Kelly's room. When you checked, you were shocked to see Kelly and Chris together.

Kelly moaned, "Ah! Chris! You're... doing great... Keep going."

Chris grunted. "Hehe. It feels good to fuck you Kelly, but we should stop or he'll find out."

Kelly breathed heavily. "Trust me. He'll never know, and even if he did, we can tell him we're drunk." She moaned again.

You covered your mouth in shock as you saw Chris fucking Kelly from behind. You were almost crying and feeling betrayed by this scene. What's your next move?