It wasn't that Jasper needed to be told twice, it was just that he wasn't used to this particular obstacle and froze up for an excruciating fraction of a second while Fury burst into the house after Mystique. When he forced himself to move again, he spun wildly in place, seeing the railing circling the staircase and landing at his periphery before he could stop himself and throwing the looped end of the belt fashioned to lead the goat over the post of it. He came to another tense stop at full circle, staring after the retreating pair before thinking better of it and rocking half a step back to vault over the railing, practically running along the wall of the opposite house as he came down into that grassy alley the goat had been so intrigued by and sprinted alongside the fleeing criminal. If she thought she was getting out the back way, she would be sorely mistaken.