I'm the Ex-Girlfriend of a Soldier

I was reincarnated as the heroine of a predictable third-rate harem novel. I decided to live as the heroine and enjoy my comfortable life with the hero… but what kind of romance story is this?! My soldier boyfriend was always flirting with other girls... and I got kidnapped dozens of times. So I broke up with my boyfriend, went on a blind date, married the blind date and… what? He was the demon king? I married the demon king.