Tell him you're not Kira.
"What do you mean you're not Kira? I grew up with you. I know
you better than anyone. We're betrothed! Are you trying to tell me
you've decided to call off the wedding?"
"Look," you say to the boy, as politely as you can, "My
name's not Kira and I don't know you. How can you say you love me
when we've never met before?"
