Cupid was the ancient Roman god of love, the son of Venus and Mars, associated with the Greek god Eros. He was generally considered beneficent, but there are many stories centered around his penchant for mischievous matchmaking.
Perhaps the most famous myth involving Cupid is the myth of Cupid and Psyche, told by Apuleius in his Metamorphoses. Venus becomes jealous of the princess Psyche for her beauty and sends Cupid to cause her to fall in love with the most heinous of men. But when Cupid sees Psyche he is himself smitten with love's arrow, and stowes her away in a secret castle where they begin a passionate affair. However Cupid only visits Psyche in total darkness, and is warned never to try to see her lover's face. Eventually Psyche prevails upon Cupid to allow her sisters to visit. Her sisters convince Psyche to sneak a lamp into her room and to wait until her lover is asleep, and take a peek at him -- just in case he is hideous. When Psyche lights the lamp Cupid is accidentally awakened, and he flees. When Venus finds out what has happened she tortures Psyche by sending her on impossible missions. Eventually Jupiter intervenes and allows Psyche to marry Cupid.