Etherege's Senex

In the first act, Medley likens Bellair's disobedience to his father as "but despising a coach, humbling yourself to a pair of galoshes," etc--i.e. it is a petty, almost quotidian social task. Both Old Bellair and Lady Woodvill complain about "youth these days" several times in the play, hinting at the young/old divide commonplace to comedy. The senex is certainly not completely diminished here, but what is the role of this "stock" character?