Christina Aguilera and Rihanna have never shied away from using their sexuality stateside, but did it get lost in translation overseas? That seems to be the case as their recent performances on The X Factor have caused a bit of an uproar.While on the UK talent show's season finale (part one) on Dec. 11, many viewers found the songstresses' performances too provocative for television.According to The Guardian, The X Factor, which airs on ITV1, will be investigated by media regulator Ofcom after there were more than 4,000 complaints about the risque dance moves and outfits in both singer's performances.So, why the investigation? The Saturday night show, which drew more than 14 million viewers, aired from 7 p.m. to 9 p.m., a timeslot known as pre-watershed hours when more "adult content" cannot be aired. The UK's Daily Mail printed pictures -- which they called "porn imagery" -- of Aguilera and Rihanna's performances and described the singers as "sex-crazed nymphs before the watershed."Aguilera, 30, performed "Express" to promote Burlesque and appeared scantily clad (with a bevy of other scantily clad back-up dancers) while bumping and grinding on stage. Perhaps we're desensitized to Aguilera's performances (this is not unlike her "Lady Marmalade"/Moulin Rouge days) but it's hard to imagine this causing as big a stir in the U.S.The same goes for Rihanna, 22, who sang "What's My Name?" to The X Factor audience. While Rihanna does strip down to her skivvies halfway through the song (rather, a man helps undress her) and there may have been too much dirty dancing for that hour, was it all really too much to handle? Watch both performances below and decide for yourself!: According to Entertainment Weekly, an X Factor spokesperson said the performances in question "were appropriate for the show" but obviously many viewers disagreed.Do you think Christina Aguilera and Rihanna's performances were too sexy for television? Chime in below!