While His Wife Watches

Anna is utterly humiliated when her cheating husband accuses her about being too vanilla during a loud confrontation in a bar. When a handsome older man approaches her and offers her a chance to prove her husband wrong then and there, she complies without thought. Will shy and 'too-vanilla' Anna be able to handle being used by both him and his wife while all the patrons watch? What happens when the dominant wife punishes Anna's cheating husband?