I have an issue with how my DH reacts to me when I am upset / angry with things my MIL does that irritate me. He says he has my back and will allow me to vent, however, in the course of my venting, he eventually starts to say things that come off to me as him defending his mom and taking her side. Then we end up in an argument about that. Most of the things she does / says that irritate me are small and passive aggressive, so most get brushed off because it would be petty of me to try and address every issue. However, it eventually gets to a point where the small things add up or a larger transgression occurs. My husband gives me the green light to vent, then we end up in the situation previously described.
A recent example is: We have a goldfish in a small fish tank on our kitchen counter. The fish has grown much larger over the months we've had him and we plan on moving him to a larger tank in the near future (within the next week or so). MIL was aware of this, as we had mentioned it to her in passing once or twice before. Due to the upcoming move, we haven't cleaned his current tank recently since we plan on throwing it out after the move. My in-laws usually babysit at our house on Tuesday evenings for a few hours so they can have time with our toddler and my husband and I can enjoy a night out. We don't always feel like going out / doing anything, but we know they really look forward to their time with our child, so we usually find something to do. Anyways, this past Tuesday, we come home from dinner and a movie to see our fish in a brand new, smaller tank that MIL had and set up for him while we were out of the house. Conveniently, she had gone home already and my FIL said she had set the new tank up and taken our old tank home with her to clean it. My husband and I told FIL of our plans for a larger tank and to tell MIL not to be offended when we give her back the small tank.
After FIL left, my husband (who was not happy with the situation either) gave me the green light to vent. I told him that I didn't appreciate MIL coming into our house and changing anything, and was especially irritated that she deliberately did it while we were out of the house without speaking to us first. No matter how good her intentions may have been, it was a rude and inconsiderate thing to do it behind our backs. She may have even endangered the fish's life since our sink has a water filtration system spigot (ok for the fish) and a water softener hooked to our tap water spigot (bad for the fish). Not sure which one she used, but we'll see how the fish does.
Anyways, during my venting, my husband eventually starts saying things in defense of his mom and trying to tell me it's not that big of a deal. I told him that if he's going to allow me to vent to him about the situation, he should either be venting along with me, or saying things to make me feel better and make me feel he's on my side. I tried to explain to him that venting gets the anger out so that a person can cool down and then handle the situation in a less reactive, anger-driven way. He just got mad at me that I was getting upset with him about the way he was reacting. How can I get him to understand that venting is an activity that involves saying things out of anger / frustration and expecting the other person to just agree to make you feel better? That once the venting is over, I'm not really going to take action on things I said like, "I don't want your mom in our house again." or "I just want to throw that tiny fish tank in the trash."?