First they went all out to be sexy. Then they covered up for a more cutesy look. And now, the girls of K-pop group Secret - Hyo Sung, Ji Eun, Seon Hwa and Zinger - are turning up the heat by going all sexy again.RazorTV reported that Hyo Sung even flaunted her C-up assets in a recent lingerie advertisement, which reportedly helped the brand sell up to 50 per cent more in January, compared to the same month last year.When asked if she preferred a sexy or cute image, Hyo Sung gave a diplomatic reply at the group's press conference in Singapore on March 17. "I think that the image of each member of our group varies. Many of us are both sexy and cute, so I feel we all suit both images."Come March 29, Secret will be returning to Singapore to stage its first full-scale concert at Marina Bay Sands Convention Hall. Do fans prefer them sexy or cute? Check out the video below to make your own decision.