Pretty Little Psychopath

This is a forbidden romance born from lies and sealed with genuine affection. Lucas Bennett, an outstanding student at Harvard Medical School, is drugged and ruthlessly abandoned by his boyfriend Jasper. That same night at a party, he crosses paths with Jasper’s father — Arthur Devine, the West Coast mafia don. An aggressive embrace and the words, “Aren’t you going to call me Daddy?” unlock the secret of a wild night three years prior: Lucas once shared a reckless one-night stand with this stranger. As vengeance, abductions and revelations intertwine, Lucas finds himself trapped in a whirlpool of hatred and love. When his stepbrother Blake sets a trap, when Jasper seeks revenge by injecting him with drugs, when Amod exploits a blood feud to coerce him into shooting Arthur — Arthur stands in front of him every single time. When all lies are torn to shreds, Lucas finally understands: the love potion sent him falling, but what made him unwilling to pull himself free was this man’s quiet “It’s alright” amid the rain, the embrace at the shooting range, and the vow beneath the gunpoint: “I’ll try not to die.” This is the story of two people cast aside by the world, clinging to each other for warmth.

Synopsis from DramaGo.