I'll try to be short.
Very recently found out that MIL gave all her family heirloom jewellery (quite valuable but more sentimental) to her other son (she has two sons, I'm married to her younger son).
She gave it to him 10 years ago, as he has two daughters and she said she never thought DH would get married or have kids as he was a 'bachelor'.
He was 25 at the time!
We met, married and have a daughter of our own now. AIBU to feel this is unfair?!
She has history of favouring BIL, DH is very hurt.