Presumably, the side project you want to work on is valuable. It's worth paying the lawyer out of your own pocket -- you want the lawyer to be working for you,

Presumably, the side project you want to work on is valuable. It's worth paying the lawyer out of your own pocket -- you want the lawyer to be working for you, not the employer. And the lawyer should not also be a lawyer of the company -- the lawyer should not have a conflict of interest.