Sweet Girl, Dirty Secrets

Alternative:

내 여자친구를 더럽혀줘 / Make My Girlfriend Dirty / Sweet Girl, Dirty Secrets / Taint My Girlfriend / Chica Sucia

Fresh out of the military, he learns his “innocent” girlfriend’s been playing him all along—and sleeping around, even with his tormentor. With the help of his childhood friend, he plots revenge to expose her true face.