Lhong Ngao Jun (2019).

Pim's half-sister, Khemjira, goes out with guys while pretending to be Pim. After getting dumped by Khemjira, one of the guys dies in a car crash. His friend, Thanakim, accuses Pim of being the cause and vows to get revenge on her and gets engaged to Khemjira so he can get closer to Pim in order to make her life miserable. Pim, on the other hand, has no clue why she's being stalked/bullied by this psychopath.