mongolian tree frog
When in a hot, humid, sweaty or tropical type climate, causing an unusually warm moist atmosphere in the crotchal region of a mans pants which creates a sticky suction type action of the penis and testicles to stick to one particular leg firmly like a tree frog.
Ie: My crotch was so sweaty after that motorcycle ride, I had a Mongolian tree frog to the right I had to pry off with a stick.