Despite the title, the song does not contain the phrase “what’s up?”. Rather, the lyric ‘what’s goin’ on?’ is prominently included in the chorus. The title was chosen to avoid confusion with the 1971 R&B song and album “What’s Going On” by Marvin Gaye. (source: Wikipedia, the free encyclopedia)
Jung YongHwa & Seo Joo-Hyun from We Got Married. Who’s with me?!