The proud moment when Lee Hwi Jae's son Suh Un walks for the first time finally arrived as shown in preview cuts for 'Superman is Back'!

SEE ALSO: Shoo's twin girls have a double play date with Lee Hwi Jae's twin boys on 'Superman Is Back'

On the upcoming episode, Lee Hwi Jae and his wife Moon Jung Won continued to help their twins to walk, concerned that they may be late to start walking as their first birthday has already passed. While they were practicing, the older son among the twins Suh Un seemed to be in good condition judging from his bright smile that day, and he was able to take a few sudden steps to fall into his dad's arms. Needless to say, this brought his parents close to tears in joy!

Check out Suh Un take his first steps on May 4!