Kieran's lips press into a thin line as he considers his (limited) options. If he were to run, Arthur could catch up to him with little issue, and it's almost a guarantee that he'd be just a little grumpier than usual.

So, Kieran goes with the option that's least likely to wind up with a whooped ass.

"Y-Yessir," he finally manages to meekly stammer as he scurries toward Arthur.