Going out on my own is GAL, but it takes me away from where I want to be...with my kids. Besides that, it just gives my W what she wants...kids and not me.
I try to go with just my kids and my W will join us or take her own car.
Advice?
It is really hard to get through to you.
let's just focus on my why you and your W don't ever want to be without the kids ever. That's really not healthy. Sure, I love my daughter more than anything, but I need some time away, with adults only. Most parents do. It's healthy for you, it's healthy for them, and it's healthy for married couples.
Stop making excuses. You cannot stay home to try to keep her away from your BIL. She'll do what she wants. It's doesn't change anything if you lessen their time together. So don't worry about what consequences you actions have on her.
Do you have friends? A hobby? Maybe it's time. it's ok to be a homebody and with your kids, but you have to really find out who you are outside of that. You might be surprised.