I was on a long flight to Asia last year, and about halfway through the flight, the captain came back to chat with FA's. He entertained passenger questions, and even had some conversations. I ended up talking to him for around two hours, and learned a lot of interesting stuff about the aviation world. For the most part, this does not happen during the flight, but on a trip where there are three or more officers up front, one is usually on break. Some choose to sleep, and some choose to chat.