わざわざ裸で踊るだけのことはある It makes sense to do naked.

Is this fast forward playback ? Don't you think so ?
They can do it because two parson. Because we can't stop quickly after speedy motion by oneself. But we can stop if other one stopped us.
The moment of starting a motion and stopping a motion, both are moment that need strongest power. Both is similar however the direction of force is different.

早送り？　そう思いませんでした？
２人だから出来ることですね。私達は自分で早い動きを急激に止めることはできませんが、誰かが止めてくれれば止まるのです。
動き始めと動きを止めるときが、最も強い力を必要とします。ただ、同じようでいて、力の方向は違うんですけどね。また別の機会に詳しく解説します。