The 40-year-old shared his sentiments in a self-shot video message to his soon-to-be bride, reported Access Hollywood. "Princess, we just completed our first weekend in Austin on 'X Factor'.
Just wanted to say I'm very proud of you and I love you so much. Congratulations," he said to Spears in the video, where he can be seen lying in bed with his head on a pillow.
Spears was touched by her beau's message and quickly responded, tweeting, "Awww love you too Xoxo (sic)." The couple got engaged in December 2011. Spears and fellow new judge Demi Lovato make their debut on 'The X Factor' this fall.