몫은

one's share

→ 몫
phrase Rare #32,301
one's share 은 marks 몫 as the topic and can add a sense of contrast.
KO: 제 몫은 제가 챙길게요.
EN: I'll take care of my share.

배는 내가 있으니 우리 둘 몫은 내가 내면 돼요.

I have a boat, so I can pay for both of us.