I have vaped all over several airports, including in the security line. Did it once while picking up my pocket stuff because the TSA agent wanted to know if it worked... I showed her! 
I've had zero problems, even at the gate while waiting for my flight.
I have also vaped on every airplane I've been on since I started. Not once has anyone said anything, including in first class where there's always a flight attendant hovering around.
Just don't make a nuisance of yourself. Turn on the little overhead air vent so it blows down in front of you. Hold the vapor in just a bit longer and then blow it downward. Don't make clouds.
Just my personal experience.
I've had zero problems, even at the gate while waiting for my flight.
I have also vaped on every airplane I've been on since I started. Not once has anyone said anything, including in first class where there's always a flight attendant hovering around.
Just don't make a nuisance of yourself. Turn on the little overhead air vent so it blows down in front of you. Hold the vapor in just a bit longer and then blow it downward. Don't make clouds.
Just my personal experience.