Treating BIL like a child

For context my partner passed away and left us with nothing, bank accounts cleaned out and no life insurance and that's a very important part of the story.My parents and in laws are extremely well and have done nothing to assist in any capacity, they just pretend nothing happened..

My MIL supports(financially)BIL,he lives in a house she owns(she lives elsewhere)and pays all the bills for him..While I work 60 hours and stick my kids in daycare and after school programs,they chose to support a 50 year old man..

They recently invited us out and I asked what the occasion was?BIL has a new girlfriend and wants everyone to meet her!Am I crazy?Is this normal?I said no we have plans,but this kind of behavior is outrageous..Don't help me but make sure to coddle your 50 son