Lee Kwang Soo and Lee Sung Kyung co-starred in the 2014 drama "It's Okay That's Love" and ever since then a few drama viewers have suggested that the couple became more than colleagues and friends. And it's not just viewers who assumed the two were an item.

Some of his "Running Man" colleagues also suggested as much.

Actor-entertainer Lee Kwang Soo is a regular on the variety show "Running Man." On one episode when the cast was playing a game of "Of Course," he was asked about his dating life. In that game, competing teams question each other and if the other team members can't answer the question with the words "Of Course," the other team wins.

The questions focused on the love lives of the contestants. Lee Kwang Soo's guest and actress friend Wang Ji Hye asked him a question that made him flustered.

"You once did a drama with someone who started off calling you oppa but eventually called you honey, right?"

He was not prepared for that question, got flustered, and said, "There aren't many people who played my younger sister."

When Lee Sung Kyung appeared as a guest on "Running Man," Yoo Jae Suk said, "Oh, is she Kwang Soo's special person, the one Wang Ji Hye was talking about?"

Comedian Ha Ha then told Lee Sung Kyung that Lee Kwang Soo had been talking a lot about her.

"He said you were a great woman."

While she may have called Lee Kwang Soo honey in private, after the drama ended she still referred to her co-star as oppa. She had nothing but praise for his "It's Okay That's Love performance in an interview she did with the Korean media outlet Newsen.

"He was serious in everything he did and was always considerate of those around him," said Lee Sung Kyung. "I think he felt more responsible because he acted out a character with Tourette Syndrome, which could be a sensitive role. He told me that he acted with a sense of mission in order to show help heal those suffering from the syndrome, instead of hurting them."

Despite the serious way he approached his role, the two had some spontaneous chemistry. The relationship between their characters seemed natural and the kisses very believable.

Are they dating or does he just have such a crush on her that he's flustered when anyone suggests as much? If they're not dating, they definitely could because they look good together. And they both seem to be sweet, thoughtful people.

Lee Kwang Soo can currently be seen in the film "Collective Invention." Lee Sung Kyung can soon be seen in the drama "Cheese in the Trap" and the 2016 film "Broker."