You know that Darllen and you are different. You are the King's daughter, while he is a descendant of a vampire, even though the vampire loves you, you can never be together. A huge barrier to love between the two of you.

"I know we are different, and will never be together. But please, let me guard your heart until you find the right soul mate."

The statement is true. But, you still want to be with him forever.