I was on DL Flight 401 on 3/5/15 from JFK-LHR with a woman sitting across from me who was traveling with her husband and little daughter. At some point during the flight she snuck off and slept in the 1 empty BE seat. She came back to her regular seat right before breakfast. Soon after, two FA's confronted her and she shamelessly claimed to have done nothing wrong because she didn't eat any of the food. I thought it was pretty ballsy!!