Lover and Kiss Riddle

A young boy on seeing a beautiful girl goes to her and says like this.

Boy : I will say a statement , if I am truthful, you will give me your phone number .. If it is a lie , then do not give me your number." 

Girl Agrees.
Then boy says some statement , hearing which the girl finds that if she does not give him her phone number she would have to kiss her.

What did the intelligent boy say?