Advice for Step-Mom's.....how to handle "Mom"

My advice would be to keep your distance.  While, perhaps, easier said than done, it is ultimately most beneficial to your ss and your home that you be the 'neutral' ground in that family dynamic.

It is beneficial for your ss because minor children are often unable to correctly interpret the behavior of the adults around them.  In short, be a stable influence in his life by posturing yourself as someone wholly committed to his welfare without threatening the relationship he may have or desire to have with his bio-mom.

It is beneficial to your home insomuchas you can create an expectation that the drama of the situation has a natural stop at the threshhold of your home's door.  No matter the outlandish the attitude or unfortunate behavior displayed betees ss, your husband, and bio-mom, your home remains a sanctuary as long as you can divest your self from the emotional toxins.

All the best.

Angela
Wife Spice Group Owner
Marriage Support Central Group Owner

I'd say it's not your place to have to handle the mom. You stay neutral because you're already the "bad" guy. You don't want to do or say anything that will make your ss resentful and you don't want anyone to think that you're trying to be "mom"