Singing is not my bag.→ 노래부르는거 안좋아해.

※ 싫어하다 의 표현.

  (something) is not (someone's) bag.
  (something)is not (someone's) cup of tea.

〔예문〕
I won't come to Karaoke room: Singing is not my bag.
나는 노래방에 가지않을꺼야.노래부르는걸 싫어해.

Thanks for asking, but ballet isn't really my cup of tea.
물어봐줘서 고마워.하지만 발레는 정말로 내취향이 아니야.