A sexual practice involving the urethra and objects which should never come in contact with the urethra.

A pubic hair piece. A toupee for the pubic area/genitals. In the 1700’s when mercury was used to treat sexually transmitted diseases (Gonorrhea or Syphilis) one of the side effects was the loss of pubic hair. To disguise this condition, that was not cured by mercury, a Merkin was employed.

A very apparent tool. A guy who is rude to girls, who thinks he is better at things than others, who is very cocky for no reason, or who thinks highly of himself for unsure reasons.
He is all that in a bag of tools.