The couple is tying the knot on April 30.
"You take away all the darkness, you take away all my pain... You walk me through the storm, through the sunshine and even the rain... You give me peace, you shower me with love and fill every moment of my life with glee...," he wrote.
Calling the Dhoom 2 actress his "partner, lover and soulmate", Karan added, "With your faith and your trust you show me not who I am but who I can be... You pat me on my back when I'm right and kick my ass when I'm wrong...
"You show me how beautiful this life is even if our path sometimes seems weary and long... You are my partner, my lover, my soulmate, my own, my friend and much more than any word can portray... I promise to be with you as you are with me forever and a day..."
The duo starred together in the horror film Alone.
This will be the third wedding for Karan, who was previously married to TV actresses Jennifer Winget and Shraddha Nigam.
Last Updated 31, Mar 2018, 6:54 PM IST