Korean Slang
심쿵
simkung
What it means
Heart-flutter — something so cute or romantic your heart skips.
Where it comes from
심장 (heart) + 쿵 (thud).
When you'd use it
Reacting to a cute puppy or a romantic scene.
Example
고양이가 손 내밀 때 심쿵했어.My heart melted when the cat reached out its paw.
Careful
Casual — fine with friends, out of place in formal writing or with your boss.