Just my thought but 1)if you can't tell her\him for fear of what they'd say then yes it's cheating. Wanking off on camera with a live person on the other end is about 1" away from doing it in the same room as them, if my wife did it without me knowing I'd consider it a form of cheating and I'd be pissed.
As long as you have agreed it is ok before it happens, then it isn't cheating. It IS cheating if you are afraid to ask and do it in secrecy or if you talk about it and your significant other thinks it is cheating.
