Behind the Shorts with Jungwon and Sunghoon 🕺 | ENHYPEN in Macau #2

In the Korean comments

One comment reads, in translation, “Actor Yang, your acting has improved,” humorously treating Jungwon’s performance like an actor’s work.

What the words mean

"웃참 영원히 못함" (ut-cham yeongwonhi motham, “can never hold back laughter”) literally says they can never manage “laugh-holding.” 웃참 (ut-cham, holding back laughter) is a casual abbreviation for trying not to laugh; here, the commenter is joking that the pair can never keep straight faces.