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They're hardly known for their shyness, so it shouldn't come as any surprise that Stellar have once against pushed the boundaries in the new music video for their comeback single.
"Vibrato" is littered with sexual imagery, some obvious and some not so obvious, many symbolizing a certain part of the female anatomy (we'll leave that up to you to guess which).
In the chorus, Junyool, Minhee, Hyoeun and Gayoung bounce up and down and rub their hands over their breasts as they sing about what seems to be, um, a woman's climax.
The video (and previous teaser clips) has been rated 19+ in South Korea and is adult-restricted on YouTube, meaning most people will need to sign in to watch it and prove their age.
Due to Korea's strict public television rules, the girls will also be expected to tone down their suggestive dance moves and revealing outfits for performances
The group's sexy image has often been met with negative criticism, especially after their 2014 release, "Marionette," which at the time dubbed as one of the sexiest K-pop videos ever.
Lead member Gayoung, 23, said of their look, "We didn't try to be erotic... We just wanted to showcase our long arms and legs, and highlights our physical features but it got received in a negative light, which wasn't our intention, so we do feel a bit sad about that."
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And she added today on Twitter, "We have no idea what’s going to happen with this song and its concept, but in a way, we’ll always come out to receive your love and support."