unpucker

verb

1. (ambitransitive)To smooth away the puckers or wrinkles (of); to relax or unclench.

   “unpucker your lips”

   “King. "Bethink you a little; I will walk about" (Gellert bethinks him, brow puckered. King , seeing the brow unpucker itself.) "Well, have you one?"”

   “How I wish I could whistle! If I could pucker up my mouth, and pitch it to just the right key, I wouldn't unpucker it in a week.”

   “Now, deep inside the Desert Camouflage Uniform pants of the most nervous staff officers crowded around SMOG stations in the palace, assholes were starting to unpucker — if not quite all the way, then there was certainly a little more sphincter breathability in the wedged-up cotton Hanes; or, in the case of those who went commando, the sandy folds of DCU'ed butts.”

   “I marveled at how any man could be so ugly as that poor soul, with his leathery pale skin and dried lips that looked as they couldn't unpucker if he tried.”