Not a pilot or flight attendant, but I fly between 100 to 150 flights a year. One time I was flying out of a small Midwest airport to Dallas. I rode up to the airport restaurant slash bar to get a **** and a drink before takeoff. I noticed this lady sitting by herself at the bar. A gentleman approaches her. He seems to be hitting it off, flirting and laughing. Time comes to board the plane. And since this was on Southwest Airlines, it was pick your own seat. Naturally, they sit next to each other. I am a few rows behind them, flirting leads to touching and then kissing. You can see that hands are wandering everywhere. By this point, I am not the only casual observer and about three or four other guys are looking and laughing. We all bond over their public display. It escalates to a point where she gets up to go to the bathroom. And then about 30 to 40 seconds later, he follows. As he approaches the bathroom, she is already in. A flight attendant stands in front of him and says, no, back to your seat. She knocks on the door and tells the lady to get back to her seat. All the observers are laughing at this point. The flight continues and she is practically mounted on him, doing everything they could possibly do while keeping clothes on. This continues until we land and all the plane. She quickly hurries off the plane. He is a few steps behind her, but she seems to be in a hurry. The other observers and I are talking about it and laughing as we exit the secure area into a baggage claim area. Then we see her still several steps ahead of the guy and she runs into the arms of her boyfriend and starts kissing him. Her flight guy just stops dead in his tracks, takes a couple seconds to observe and then just leaves. I haven't laughed so hard in public with people I have never met prior to or since.