I'm not even sure if I'm going to do this one, but here's a title page just in case I do.
So like, I didn't have anything planned out for this one. Pinkie and Cloudchaser were just two ponies that I chose at random to enter the spa, and people want to see their action. So the storyline I would think is:
Cloudchaser is visiting Ponyville for the first time, and Pinkie Pie, having never seen her before, jumps at the chance to make a new friend. She shows Cloudchaser around the town, and they end up at the spa, where Rainbow Dash was just leaving. Curious, Cloudchaser wants to try the service that Rainbow Dash had just received.
Consequence of being in a rock farm.