When a male drops a steaming duker on across a female's chest (making a shit bridge over her tits (left nipple to right nipple)). After defacating, the male slides his penis between the breasts (usually accompanied by lubricant). The female then leans up and sucks on the head of the penis while it is in between her breasts, occasionally taking a nice taste or bite (if you will) of the wonderous log that the guy steamrolled on her chest.
I walked in on my mom being hot karla'd by my dad. It was very erotic, and smelled horrible.