Go to the end of the hallway towards the last room. Collect the yellow pencil from another room upstairs.Go to the bathroom, the first door on the left, and look for Madison’s phone near the sink. Go to the Master Bedroom, it is upstairs the first door on the right.The bathroom key is in the garage, look on the left shelf as you enter. Collect the mysterious key on the left of the Fireplace next to the white vase.
This will increase your friendship with Madison. The House Party walkthrough is divided based on different characters and interaction results with them.