"Okay, here." Billy first tries carefully vaulting up, a move he'd seen Kimberly try on the gym mats many times. He fails to gain enough momentum and falls. "Oof, alright!"

He reluctantly clambers up on the rock, fixing one foot into the stirrup. He just has to swing the other over, not...fall. Again. By now, he's completely flushed with embarrassment and patting the horse in apology. "I'm sorry. Here, one more try," he calls, pushing up and leaning over rather awkwardly. Soon, he's straightened everything out and nudged---forward, right?