The Wonder Girls are the first Kpop group I knew about and loved when 남자친구 first got me into Kpop!
두근두근: an onomatopoeia for a heart beating/pounding
의심: doubt, suspicion
나타나다: turn up, appear
모습이: figure, form
제발: please (Note// From my understanding, 제발 isn’t used in the same way ‘please’ in in English e.g. “Please hand me that pencil”, rather 제발 is used for begging e.g. “Please forgive me”, “Please leave me alone!”)