Backstage of last week's MBC's 'Music Core', 2PM and 8eight performed a song swap by singing each other's songs! A video of the performance was recently uploaded onto YouTube and has been garnering immense popularity from fans of both groups. Instead of the sad and emotional concept they have on stage, they had fun with 2PM's song. Since the two songs contrast greatly in mood, fans were delighted to see 8eight go for a more upbeat style with "Hands Up" and 2PM deliver a smooth cover of "Close That Lip". Joohee especially seemed very happy to see the boys of 2PM and jammed it out with them. The two groups later exchanged CDs and yelled out "Fighting!" as a message of support.  Netizens wrote, "It's nice to see them cheering each other on", "8eight has a little kid side!", and "I hope both of them are successful!" Check it out below! Source + Photos: BNT News via Nate