Complications with spouse and MIL with ADHD

My situation is complicated. Not only am I dealing with an ADHD spouse (diagnosed as a child) and I think we deal with that fairly well, although there is room for improvement, but I am also dealing with an undiagnosed mother-in-law. Sometimes I feel like more of the problems in our marriage surface due to her than anything else. The biggest issue is that she has no boundaries …..

She is moving at the end of October and will be without a home for a week from the time she moves out of her existing townhouse and into her new home. She has asked my husband if she could stay with us, which he said yes to without talking to me! Anyway, she has a little dog that the kids happen to love, however this dog is destructive. When I questioned my husband about the dog he got defensive and said that I always make things difficult. I feel like I just want to make sure we are all on the same page as to how we will handle having the dog for that week. My husband starts with his usual rant that I am controlling and negative. I feel that I am cautious, like to plan and like to set boundaries.

My MIL has no boundaries. In fact I doubt it has even occurred to her as to where the dog will spend its entire day while we are all at work. This is the same woman that rented the present townhouse she lives in with the strict stipulation that she may have 1 dog. 2 weeks after moving in she got another dog. When we questioned her about violating the terms of the lease she replied “That’s the landlord’s problem”!!!

I really don’t know how to deal with this without putting my husband in the middle of it all.   His response to all of this is:  "With the tug of war I get from you and my mom I feel like sometimes just taking off. But I don't because of my boys."  Help!