The Demon King and the Hero's First Kisses Are Mine!

Also known as "The Demon Lord and the Hero Aren't Actually My Past Lives?!"

I looked at the Demon Lord's younger sister and the Hero's older sister and said, "The only first kisses in your family that weren't mine are yours!"

The Demon Lord's younger sister and the Hero's older sister heard that and both turned to stone!

"But they don't like me, so what can I do about it?"