2 Part Technique - Counter the Stacking Pass with an Elbow Push, and if your opponent continues to hold onto your legs, sit up and grab his far shoulder, making sure he cannot reach around your head. If he tries to lift and pin your back to the mat, go with it; essentially, performing a backward roll over your shoulder and establishing the top position over him. If he doesn't try to lift your legs up off the mat, force his reaction by shoving his face toward the ground. When he post up off the mat in response, swing overhead and land in Side Control. If he still yet does nothing but hold your legs, free them by splitting your legs apart, and coming up on top for Seatbelt Control. Try and catch his arm in a crucifix on the way up, since it will be easier to apply and finish with the Rear Naked Choke from Crucifix.