Actually, my thoughts go back to Vanessa's situation and how this worked for them. I doubt Vanessa uses "schemes" to cheat on her wife. Yes, I could be wrong but Vanessa is apparently very much in love with hers and didn't want to lose her.
Obviously lying is usually a bad thing in and of itself but telling your wife she's not fat (when she is) still is technically lying. That's why I say it's the motives that count.
I've had 2 ex's that were pathological liars, that lied just for the hell of it (psychological problem). It can leave you in a daze when someone lives in their own fantasy world like that.....I had to keep reminding myself they weren't doing it intentionally to harm me. (but they obviously weren't trying or able to protect myself and others from their problem, either)
It's not a good practice to go around lying but there are instances where (deception) is a (necessary) means to an end.