Shoo, who was a part of SM's past darling girl group S.E.S, featured as a guest on 'Radio Star' today, chit-chatting about many different topics. 

SEE ALSO: Seo Min Jae exposes personal conflict amid pregnancy news "What should I do if you leave me now that I'm pregnant?"

S.E.S was one of the biggest girl groups of early millennia along with Fin.K.L, and it was no secret that the two groups saw each other as rivals. Though Shoo didn't personally broach the topic of the rivalry, the MCs, ever the devil's advocates, mentioned how S.E.S had branded themselves as a girl group of class. MC Kim Guk Jin asked the singer, "Didn't you guys once say that 'there would be no group like us in the future because we're too high-class' or something like that?" 

Shoo elaborated, "We were a posh group. We couldn't even use the public bathroom comfortably," joking about the group's then-image. When the MCs accused her of throwing shade at Fin.K.L, Shoo explained, "I think there was a thing about Gangbuk and Gangnam," referring to the fact that Gangbuk, which is north of the Han river, has a connotation of being grittier and less posh, while Gangnam, which is south of the Han River, is known for being a high class, upscale area. 

She continued, "S.E.S was Gangnam style." When the MCs teased her, "So what is Fin.K.L then? Gangbuk style?" Shoo only sputtered, "Wait, Hyori unnie... let's just pretend this didn't happen," making the studio burst out into laughs as Shoo seemed scared of what Fin.K.L member Hyori may say to her!