CM Punk is set to challenge Gunther for the World Heavyweight Championship at WWE SummerSlam. However, footage from January recently surfaced showing them breaking character and sharing a moment backstage.Netflix released a five-part documentary called WWE: Unreal, which showed how things operate in the backstage of pro wrestling. It included a lot of unseen footage from the past year, including RAW's debut on Netflix.On that show, CM Punk took on Seth Rollins in the main event. But before the match, Punk spoke to Gunther and Ludwig Kaiser backstage, asking them to critique his match with Rollins and tell him what they think of it.Here's how the conversation between The Second City Saint and The Ring General went:"So you guys are my brutally honest European friends. Tell me how it is when I'm done, okay?" Punk said."These are the moments we’re doing it for. High pressure, big expectations," Gunther replied."Yes, I told Hunter today you know I'd made this big thing 10, 12 years ago about the main event of WrestleMania. Boy, did I f*cking get what I asked for," Punk responded.For those who want to see the footage, it's in the first episode of WWE: Unreal on Netflix at the 45:05 mark.Gunther is feeling excited about facing CM Punk at WWE SummerSlamFor the first time on WWE television, Gunther and CM Punk are scheduled to go one-on-one at SummerSlam. They previously battled several times on live events in December and March, with The Ring General getting two wins against The Second City Saint.Speaking to Radio Times earlier this week, Gunther opened up about his feelings on facing Punk at SummerSlam. He's excited and looking forward to battling one of the "most unique" WWE Superstars."I'm looking forward to getting in the ring with (Punk) on a big stage like SummerSlam in a prominent spot like that. That's why I joined the company, I wanted to be in the ring with the top, top guys and him coming back was a big deal, he’s one of the most unique performers that the business has ever had," Gunther said. [H/T: SEScoops]CM Punk vs. Gunther for the World Heavyweight Championship is scheduled for Night 1 of SummerSlam on Saturday inside the MetLife Stadium in East Rutherford, New Jersey.