The 30-year-old former Mousketeers were once touted as rivals, but Christina put pay to that rumour by Tweeting, 'Hey @BritneySpears Congrats on Femme Fatale release! Can't wait to see what you bring in the next video. xo - Xtina (sic).'
Spears returned the compliment, replying that she was looking forward to watching the Burlesque star in her new role as a celebrity mentor on NBC's upcoming talent show The Voice.
'Thanks @TheRealXtina,' she wrote. 'Can't wait to watch you on your new show. Hope we get to hear that voice on The Voice.-Brit.'