When you are working with your product manager, on a project, it quite often happens that they have some really weird requirement. A requirement that you just cannot understand why on earth, would anyone want it.
For example, take a look at this amazing video :
But, you being a software craftsman, take it up as a challenge, and code it up. You're not happy, as its made you mess around with your beautiful code, leading into a lil bit of spaghetti. But it works. You've accomplished the requirement.
Next time this happens, say No.
And rather ask, what exactly is it, that the business requirements from this feature are.
Ask whats the problem that is being solved with that feature.
And then, make an informed decision whether the proposed feature is the best way to solve the problem.
If you think it is not worth doing the way its been asked, mention your reasons for not doing it.
But, always suggest alternatives.
The key is to communicate.