So my husbands mom's birthday is tomorrow and we've been planning for weeks to go to his brother and wifes house to celebrate her birthday.

So today at the last minute something came up, and they canceled. (it was a bullshit reason) his mother calls me and is crying her eyes out, and I'm obviously trying to console her. She's paranoid that her son doesn't want her to see her grandkids. Which this isn't the first time they've done something super sketchy. They honestly treat her like dirt, and my husbands mom is a loving, caring grandma that would do anything.

Do I confront my sister in law and brother in law or do I stay out of it? Again, this isn't the first time she's cried to me on the phone because something like this happened.