That moment after you jump in the pool but before your genitals get adjusted to the cold water. Also for sitting down in a very hot tub.
1 - As Jimmy jumped in the pool, a thermal crotch transition occurred, and he yelled, "Ahhh my krundle!"

2 - As Jimmy sat down quickly in the hot tub, a thermal crotch transition occurred, and he yelled, "Ahh my krundle!"
by Mayo Therak Rotch May 9, 2011
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