At lovers’ perjuries,
They say, Jove laughs.

– William Shakespeare

Romeo and Juliet, Act 2, Scene 2. Juliet’s comment is an allusion to Jove, or Jupiter, who was the Roman king of the gods and was associated with thunder and lightning. The saying about lovers telling lies comes from Ovid’s Ars Amatoria: "Jupiter from on high smiles at the perjuries of lovers." Juliet has just asked Romeo if he loves her, and before he answers she suggests that even if he swears he does he may be lying.