Slippery Turtle
A Slipper Turtle is when a man is very bored with sex, and just wants to end it. The man will be looking for a way out, to end the sex and just get out of the situation. Keep in mind however, they must be performing anal sex with the girl. He will act as though he is close to a climax, and inside of ejaculation inside of her, he will urinate inside her anus. The phrase has to do with later in the day\\evening when the female must perform a bowl movement. The urine will make the movement slippery, and the movement is referred to as a 'turtle'.
Man: Dude I gave Female a Slippery Turtle, she said it was the easiest turd she's ever passed.