sneaky
Eqeus uses the word "cunning" to describe Lysander, and says that he "filch'd my daughter's heart". He is not trying to compliment Lysander on his trickery, so using words that have a positive connotation here would not be appropriate. He does not respect Lysander for his actions either. He sees him as almost traitorous and backstabbing like a thief, stealing his daughter away. Sneaky would be the best choice because it does not carry a positive connotation.