Katy Perry is writing a love song for fiance Russell Brand.
The 'California Gurls' singer - who got engaged to the British comedian in December after a whirlwind romance - is planning to serenade Russell with the romantic tune when they get married later this year.
A source explained: "Katy has written a love song for Russell. She's planning to sing it to him right after they exchange vows.
"She can't wait to see the look on his face. It's going to be the most emotional moment of her life. Katy's fallen head-over-heels for Russell and isn't afraid to show everyone her inner feelings. She thinks that the best way she can express herself is with romantic lyrics."
Katy, 25, recently revealed she and 35-year-old Russell keep making up stories about their impending nuptials so people will be surprised when the big day finally arrives.
She said: "Russell makes up these really crazy stories about me and our wedding. I make up stories, too - I said he was a 'groomzilla'. He said I farted a lot, but I've never farted in front of him - honestly!
"I hear these crazy stories - we are going to get married in latex, underwear, in Spandex, in Japan, in India, in Thailand. But I think all this craziness about my marriage is really funny.