My Fiancé Said He Wants to Take a Commoner as His Mistress — I Don’t Want to Be a Decorative Wife, So I’ll Bring Him Down Alongside His ‘True Love’

婚約者から「平民を愛人にしたい」と言われた私－お飾りの妻は嫌なので「真実の愛」と共に破滅させます－