After he famously tried to chat up former panelist Cheryl Cole on last year's series, the Biebster attempted to work his magic on the next generation of female judges during his performance of festive track, Mistletoe.
The 17-year old serenaded both Kelly and the N-Dubz stunner, as he jumped on the judging panel to direct his lyrics about kissing under the mistletoe to both ladies.
After his performance - which was apparently pre-recorded - XF host Dermot O'Leary commented on Justin's flirty antics, to which the Never Say Never hitmaker replied: "Sorry man, it’s a habit.”
Following Bieber's stint on stage, Destiny's Child star and panelist Kelly Rowland left her seat to perform a medley of tracks, including her new single Down For Whatever.
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