boab dab
Originates from the Scottish (See Scots) word Boab or Boaby, meaning penis (also see Chobber). Refers to a small damp patch made on ones underwear/trousers after contact with excess urine/semen left on the tip of ones boaby.
"Ah hud tae go commando theday and managed tae get some boab dab oan ma jeans"