Dallas

 In the "Dallas" TV series, Mark Graison had a professional and somewhat friendly relationship with Cliff Barnes. Mark was a business partner and associate within the Barnes-Wentworth Oil empire, which Cliff was heavily involved in. Their connection was mainly through their shared interests in oil and the family business, intertwining their lives via the ongoing rivalry and alliances among the Ewings and the Barneses. Mark’s significance in the series is largely tied to his romantic relationship with Pam Ewing, who was Cliff Barnes’ sister, adding another layer to their interactions. While Cliff and Mark were not depicted as close friends, they maintained a working relationship connected by family and business dynamics.