'Barefeet Friends' Lee Hyori and Eunhyuk revealed their 'gum smiles.'

In SBS "Barefeet Friends" aired today, the members left for a retreat to a mountain.

On their way to the destination in the war, Super Junior's Eunhyuk made Lee Hyori happy by saying "Something about today makes me feel good." At this, Lee Hyori said, "Eunhyuk's mouth gum is nice too."

She continued, "There are best of gum smiles in the music industry. Lee Hyori, Eunhyuk, Jun Hyosung." Eunhyuk then added, "They're also in the acting industry. Won Bin, Lee Sun Kyun."

Lee Hyori then said, "Let's smile," both of them revealing their bright trademark smiles that show their gum.

Photo Credit: SBS