The loop between the third and fourth knots went around Felix's stirring cock and balls. He caressed Felix's groin gently, just because he could, before placing the fourth knot against his lover's perineum. He guided the rope between the cheeks of Felix's rear end and up his back. There he slid the ends through the loop at the back of Felix's neck. He made a slight adjustment to make sure everything was where he wanted it and asked, "is that okay? It's supposed to get tighter as I go so I don't want it too tight to begin with."