I know it looks like a joke or that I'm making it up. Here's a better pic and description. from a website with a lot of good stretches. I guess we didn't make up the name they call it Big Hurt too.
We call this stretch the 'big hurt.' This is a great stretch for the groin. Spread your legs out as far a they can go (kind of like the middle splits from your knees). Put you elbows on the floor and push your body backwards trying to touch your butt to the ground. This is also great with a partner. Have the partner sit behind you and put their feet in the back of your knees. Have them push on the back of your knees and pull your torso towards them. Only then will you know the true definition of 'big hurt.'