In most of the experiences I have had with non-smokers commenting about no smoking, I just educate them on the device and the process of vaping.
... preferably ahead of time.
I've been boring people in the office about my new vaping "gizmo", to prepare them for when I start taking hits off it in my office. (The whole building is non-smoking, other than the loading dock, five flights down.)
Fortunately, in VA, the State Attorney General recently overruled the Health Dept bureaucrats and verified that e-cigs are *not* subject to the state smoking bans.
I've actually had non-smokers point out that I can use it in the office.
I've also found that vaping pure unflavored PG produces hardly any visible vapor, especially exhaled.
You could take a huge hit on the PV, then blow out ... nothing at all, visible.
Adding even 15% VG to PG produces a lot of visible vapor, compared to pure PG.
(It also notably reduces the TH.) So pure PG base would probably be preferable for "stealth vaping".
In a debate on a car forum, I noticed that there's practically a conditioned response against smoking, in a significant chunk of the population. Since it seems to operate at the emotional, rather than rational level, it would trigger on vaping, as well. So it's probably a good idea not to get in people's faces with it, until more people know what vaping is.
I wonder if anyone makes a PV that looks like an asthma inhaler.
That being said, I'd probably reach my limit on tolerating Walmart before I'd need to vape.
(Although I wonder if you could clear the "express" lane with one of Churchill's cigars.
)