He either needs to learn to a) STOP HITTING POTHOLES ALREADY BECAUSE IT DOESN'T JUST BEND THE SEATPOST, IT BENDS THE HELL OUT OF YOUR RIMS AND POSSIBLY YOUR FRAME AND FORK AS WELL, WHICH GETS EXPENSIVE IF YOU'VE FALLEN ON HARD TIMES, b) buy a few cheap dimension / kalloy seatposts and replace as needed, or c) buy a suspension seatpost so he won't have this problem.
What is it about bicycles that turns every mildly deranged person into a fabricator / customizer?