A 60-year-old man from Kandivali (West) has lodged a police case against a woman he was dating, her daughter and her daughter’s friend for allegedly blackmailing him by threatening to tell his wife about his affair and then extorting money and valuables worth nearly Rs 37 lakh from him. The Kandivali police arrested the woman’s daughter’s friend on Friday and are looking for the mother-daughter duo. According to police sources, the 60-year-old, who works with a real estate company, was in touch with the accused woman for the past few months, and the two were in a relationship. The woman, her daughter and her daughter’s 21-year-old friend then started blackmailing him. As per the police complaint, the accused youth robbed Rs 14,500 cash from the complainant at knife-point while dropping him at his house on August 23. “The trio between August and December extorted money from the elderly person by threatening to tell his wife about his illicit relationship. By blackmailing and threatening to kill him, they extorted Rs 30.88 lakh in cash, Rs 3.98 …