It Happens on Valentine's Day

Muenprae cheats on Tan, a boyfriend she is soon to marry, to have a secret affair with her married supervisor, Wiwat. On Valentine's Day, the two decide to celebrate their love on their own. However, Tan and Yuwadee, Wiwat's wife, get wind of it and finally find the truth.

Kim's life is surrounded by three men. Aek; a cheating boyfriend, Sira; a man who wants her to be his official mistress, and Tan; a man who does not want to be serious with her. Despite these three men, she has to spend Valentine's Day alone.