The Prime Gig (2000)

Pendelton "Penny" Wise is a smooth-talking con-artist who makes a living by scamming people with phoney travel comp vacations over the phone when, desperate for more fast cash, he's called to work for a shady, veteran con businessman, named Kelly Grant, in selling property for a gold mine over the phone, which takes a turn when Penny begins a relationship with Grant's mistress Caitlin, where Penny throws common sense and caution to the wind to woo her, while we wonder who is scamming who here.