In one past episode of KBS' talk show 'Happy Together', Yoon Si Yoon revealed what kind of person he becomes when he is madly in love.

He went on, "It was right after she told me, 'I miss having Busan style sundae gookbap.' You know how it takes hours just to get there, right? I went there, got sundae gookbap takeout, and returned to Seoul on the same day."

Yoon Si Yoon shook his head and said, "No, it was too much for her. She creeped out and was like, 'Isn't this too much, oppa?'"

The actor said, "The problem was the cake only lasted for a day, because it was half-baked. So, I asked my friend to put some ice around the cake when he/she was bringing it to Korea. I gave that to my girlfriend at that time and explained what I did to make sure it didn't go bad, she said, 'You know, I'm getting so sick of you.'"
Then, he added with a laugh, "We broke up soon after that. She dumped me."

(Lee Narin, Credit= KBS Happy Together 3)
(SBS Star)