Actor Lee Jong Suk�shared that he felt a little intimidated by co-star�Seo In Guk's body on the 'No Breathing' set.

At the press conference for the film on the 22nd, Lee Jong Suk was asked if there was any real-life rivalry between him and Seo In Guk, who also play rivals in the movie. Lee Jong Suk said, "There were a lot of scenes that we went topless, so I worried a lot about my body. I'm skinny, my bones are thin, and I'm pretty pale. That's why when I saw myself next to Seo In Guk hyung in a scene, I felt I looked like a Q-tip. If Seo In Guk said he didn't eat a meal, I ended up skipping a meal too and exercising more."

Seo In Guk also had his own insecurities, however. He shared, "I'm shorter than Lee Jong Suk, so that stressed me out. I fixed my posture, but I still didn't look as cool."

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'No Breathing', also featuring Girls' Generation's Yuri, will hit theaters on October 30 KST!