My guts were tightening just thinking about Allyson's suggestion, which made far too much sense.

The German was good, Michael's guts tightened as he realized it.

His gut tightened whenever he allowed himself to think of those few passionate moments.

The nightstalker's gut tightened, angry, like a fist inside of him.

His guts tightened, reminding him that he was deceiving himself.

As she went by, he smelled lilac and his gut tightened.

Mason's gut tightened as he wondered what Trimble was getting at.

His gut tightened as he looked into Amanda's eyes and saw the pain and anger there.

As Casey walked back into the room, his gut tightened.

The scent of blood was strong, and my gut tightened.