There have been a considerable amount of posts here that decry the dishonesty of employers in the field of EFL China. Perhaps even you have bemoaned the truth of that; after all, it is obvious to anyone that has been here for awhile. Nevertheless, you advise another poster to lie. That being the case, aren't you justifying the lies of employers and suggesting that lying is a useful means to an end?

I'm not trying to take the higher road here - I'm as fallible as the next guy; however, it would seem to me that if we expect honesty, we should exemplify the same by our own actions. I would, therefore, advise the poster to tell the truth. That truth being: "I don't want to do it, so I'm not going to do it." On the other hand, if he/she has at a prior time agreed to take part in x amount of outside activities, be it a written or oral agreement, then there is an obligation to do so.

Liars when they speak the truth are not believed.
Aristotle