The Heart Wants What It Wants

The heroine's mother performed a successful surgery on the hero's grandfather, leveraging this to insist that the hero and heroine get married. Despite their marriage, the hero remained indifferent to her. They had an unintended encounter after being drugged by separate parties. Taking advantage of the heroine's departure, the supporting female character stepped in, causing the hero to mistakenly believe it was her. The next day, upon seeing the heroine with birth control pills, the hero concluded she had cheated.