My Ex-Girlfriend Cheated? My Response: I Don't Want Her Anymore

[Cheating and face-slapping + no System + satisfying revenge + alternate world + multiple heroines + ruthless protagonist]

I was delivering takeout to a hotel when I heard my girlfriend moaning inside.

I spent money supporting her, only to get cheated on.

Angry? Want revenge?

Good!

Just watch how I make her regret it!