Public Display of Affection on Facebook, usually when a couple publicly swoons over each other, when they should just text each other, pick up the phone, or heaven for bid just talk to each other to save the rest of us from the cheesy and showy interaction.
Person 1 is ... "I love you sweetie"
Comment ... Person 2 ... "I love you too my love! You're the best! I'm so lucky to be with you"
Comment ... Friend ... "Enough with the Facebook PDA"