Hong Jin Young has doubts that Heo Kyung Hwan is single.

On the December 29th installment of 'My Little Old Boy', Hong Jin Young and Kim Young Chul visited the home of entertainer Heo Kyung Hwan. After checking out his restroom, Hong Jin Young commented on the two toothbrush holders that were stuck to the wall.

"Someone else lives here," suspected Hong Jin Young. When he sensed that Hong Jin Young began her guesswork, Heo Kyung Hwan explained, "I put two up there since I thought that the one toothbrush would be lonely."

"They are both in tatters from frequent usage. I think someone was here until this very morning. It feels like you took out the toothbrush last minute, knowing that guests would come," added Hong Jin Young.

As the trot singer's investigation continued, Heo Kyung Hwan nervously responded, "It's my mother's."

Refusing to let go, Hong Jin Young teased Heo Kyung Hwan, "Your mouth is drying. You keep licking your lips!"

Meanwhile, the permanent members in the studio smiled at Heo Kyung Hwan's reactions.