Nine Muses are back again with their music video for latest song "Glue"! Though most people are familiar with the '19+' mature rating, the girls have been getting fans excited with a '25+' warning from the start of the teasing process, writing on Twitter, "Comeback teaser image revealed! Digital single Glue will be released on December 4th. 25 rated! Look forward to the dramatic new transformation of Nine Muses." They gave a hint as to why it's rated so high with their sexy teasers, and now you can see what it's all about and if it really lives up to the '25+' rating they've given themselves. Check out the girls' sexy MV and concept for their comeback track "Glue" above! [Update] - The girls' agency has updated fans about what they meant regarding the 25 rating they previously mentioned. According to the most recent press release sent out after the release of the MV, the agency reveals that the '25 rating' they mentioned was meant to serve as both an indicator of the girls' sexy image and their sexy choreography, as well as the girls' average age reaching 25.