The Essence Of A Perfect Marriage

My husband is in love with my younger sister. And of all things, I found out about it on my birthday, which is also the day I died. But… I somehow traveled back to one year ago?
The day I came back from the dead, I decided. This time, I have a year to seduce my younger sister's man and marry him. Until then, I'll get my revenge.
But this guy… Why is he so perfect? He's a second generation conglomerate heir, and during this contractual relationship, his eyes… his lips… I keep getting mesmerized.
'What should I do…?'