Party At The Neighbors (Third Wheel Series 1, Book 2)

"That noise! I'm going to kill them!" Tom tries to get in the big man's way, but Nick is already out the door with his tennis racket in hand. "What are you doing?" the man yells outside. A door crashes; screams; silence. Tom rushes up beside his massive boyfriend. Oh... Men are moving, squirming, pandering and twisting. The neighbors are having a sex party and the star guests have just arrived!

This is the second book in this series. You can find all four in the Third Wheel Collection 1.