pucker
v.β Β«βNo matter how many times you do it, you still pucker once you get over the wire,” says one of the helicopterβs pilots, Chief Warrant Officer Lance Duensing.Β» ββThe Doctors of War” by Bob Drury Menβs Health Jan. 30, 2006. (source: Double-Tongued Dictionary)
Pucker – refers to the action taken by the sphincter or βbutt holeβ when the human body is experiencing great stress or fear. Commonly referred to as βthe pucker factorβ
Yep, that’s right. No mystery there.