
I think so too, Sunhwa and Mokyeon's friendship is peculiar. I'm not sure if he'd step aside to help Mokyeon, considering they have cheated on their partners before with each other.
But they've been friends for 10yr, and actually know each other well. Sunhwa noticed Mok was seeing someone, and Mok knew Sunhwa wasn't serious with Nanjo.
Honestly i can't completly understand that kind of relationship if you're really friends.

They use other for convenience but i do think he thinks of MK as a friend.
Both of them aren’t great people and are both using Nanjo in some way. But I truly believe whatever Sunhwa has with Nanjo isn’t bigger than his decade long friendship with MK. I feel like he would have been more receptive to this if he had been told outright instead of going behind his back
Am I the only one who feels like their friendship actually matters to Sunhwa and he would have helped Mokyeon if he had been truthful.