It means the same as the phrases, "you bet
your ass" and, "you bet your dick and balls".
That is, you'
re absolutely, positively, 100% certain about the final outcome of a
situation.
{Seen on a website about flashlights, LEDs, and lasers}:
I tried to cut through the outer casing to
bare metal with the blade of a Swiss
army knife, and with some minor difficulty, I was able to do so. This shows the
unit has a Type II anodized finish to it (...)
Would I really cut up a brand spanken new $450.00 laser? You bet your sweet patootie I would, if it's in the name of science.