OK, I came up with this today and it may be the most powerful ligament stretch ever. This is how the exercise is performed. First grab your penis from behind, as you would in a Behind The Cheeks Stretch. Now stretch your flaccid penis behind one leg. In this position squat down. Once in a comfortable position the murder happens...START TO DO ROTARIES! WTF is that pain? That is SERIOUS, DEEP, LIG STRETCH. I did 30 on each side and I was ready for a break.
Here is an illustration
Here is an illustration