it's an old person wrinkle which has dirt, sweat, blood, and grease build up in it and create a putrid stink. When they slobbery kiss their grandchildren it pours out all over their grandchild's face. The wrinkle stink's juice was actually used as a torture method in ancient china and they would collect old Asian men and take their wrinkle stink's juice to pour over war prisoners for info.
Did you see that old guy Ashley is dating? He's older than the last guy! I guess that nasty girl really does like to rock the wrinkle stick or something.