We Still (Be With You) | MYUNGHYUK

To say Myungjun had something against love itself would have been a lie: he didn't. More or less.
What he actually hated was being the piano man for a bunch of disgustingly lovey-dovey couples on S. Valentine's Day -that was his problem, and he just wished he could run away from that pink, heart-shaped hell.
Until the most beautiful stranger he had ever seen walked in and he immediately crushed on him -only to realize that said guy had a girlfriend.

Or: Myungjun falls for an already-taken Minhyuk, Bin and Dongmin are awfully in love with each other and Jinwoo is the supportive friend who brings alcohol at parties. Sanha is simply too done with everyone to care.