A Simple Fucking Gesture

A male driver and his wife in the passenger seat, discussing a current somewhat mundane issue in her work life, are inching along in gridlock when another driver tries to cut into their line. The husband's nerves already frayed, he relents on his wife's advice. Their collective frayed nerves are ratcheted up a notch when the other driver does not acknowledge with a friendly wave the husband allowing him to cut into their line. The vitriol in their car over the inaction of the other driver reaches a boiling point including a gesture by the husband for the other driver to pull over. Complying, the other driver pulls over followed by the husband and wife, stops, gets out of his car, and approaches theirs, they having nowhere they can go. How are they going to get out of this confrontation, what they now perceive as potentially violent?