How come I cant do a scorpion (cheerleading move)?

Im 16 years old a junior in high school. and ive been cheering for a yr and a couple of months now..i can do a heel stretch, and a bow&& arrow but i just cant seem to get a scorpion. Im very flexible, and i stretch every other day. Idk if its because my butt is too big or what i jus need some help because our compotition is coming up and i want to be ready and be able to do all the things a flyer is supposed to do. please someone help me !!!!