When a Bernie Madoff type goes to jail, what becomes of his offspring left behind? Debut feature writer/director Joey Kuhn explores this thorny subject in “Those People,” set in the oh-so-familiarly gilded world of Upper East Siders.

He’s got a magnetic presence in Jason Ralph (“The Magicians”) as Sebastian, the hard-partying son of a disgraced financier — but the film centers instead on his mild-mannered best friend Charlie (Jonathan Gordon), torn between his loyalty to Sebastian and a blossoming relationship with a classical pianist (Haaz Sleiman). And Charlie is a nice, sensitive guy who’s, frankly, just not that interesting.

“Those People” also suffers, perhaps, from a lack of timing; Kuhn’s group of one-percenter millennials harkens back to early Whit Stillman or, more recently, “Gossip Girl.” Their Champagne-drenched, trust-funded angst feels musty in today’s climate — though Charlie and Sebastian’s favorite drinking game nicely points out that Gilbert and Sullivan lyrics are completely timeless.