PBI-EWR 737-900 early morning flight asked FA bringing around tray of water & juice if I could have a bloody mary. She said, "Not now, but once we're up in the air." I replied, "Sounds good. Thanks!" Then when I got up to pee before door closing, I asked the other FA who was in the galley, "Hey, any chance of a bloody mary? I'm heading home and it's been a tough trip." He replied, "We're not allowed to, but I don't care.", and proceeded to make me one.