Lee Seung Gi and Suzy got suspiciously close on the set of 'Book of the House of Gu'!

The drama released still cuts of the pair fooling around on set. In two of the photos, Lee Seung Gi was grinning broadly as he patted Suzy's hair. In others, he had his arms slung around her in a playful headlock, and the pair were laughing and smiling.

Reportedly, they filmed the scene with no dialogue, and was recorded with the intention of showing their playfulness while enjoying each other's company. As the pair didn't have a set script, many were impressed with their improvisation skills. The staff members were also awed with how realistic their chemistry was. The PD stated, "Both Lee Seung Gi and Suzy give off an infectious fun energy on the set. Even though the filming is grueling and takes up a lot of time, their chemistry is a big help to everyone."