Big thing with stealth vaping on planes is just to remember that the smoke detector in the toilets can pick up the vapour - so if you do vape in the toilet, hold it in a little bit longer and exhale towards the ground or into your clothes - and even if it does set off the smoke alarm and you get confronted, just play dumb
no ma'm, I wasn't smoking, I'm not even a smoker, do you smell smoke?
no ma'm, I wasn't smoking, I'm not even a smoker, do you smell smoke?