So, context time. "Simon" is my cousin, however, his mother was an extremely negligent drug user who divorced his father and shacked up with a drug dealer and extremely dangerous man who did unspeakable things, which he was convicted for. During the divorce battle, Simon and his younger brother (isn't really relevant to the story) were placed in the legal care of my parents. At the time, my parents believed they could never have children, and had always doted on the boys, however now they were legally living with them.

Eventually, after my mother testified in court against their mother (her sister), their father was given full custody. However, they remained extremely close with my mother and father. I was born a few years later, and their dad eventually got a new partner, who we'll called Megan. Megan is an incredibly harsh and unfeeling individual, who has two biological children who have severed all contact with her for how she treated them. She treated Simon and his brother just as cruelly, even worse on occasion. She would regularly kick them out in the middle of the night and leave them homeless, many times leading to them staying with us. She has mellowed as they got older, presumably because they're the only ones who are still in contact.

Now, it's Simon's 30th birthday in a few weeks, and Simon's fiancée, Hailey is arranging a surprise birthday party. We've known Hailey for years now, and we've never had any cause for worry or tension or anything. Until now.

My mother's wheelchair bound due to some severe health reasons, and Hailey is very aware of this. However, when we last saw her, she told us that the surprise party is being held at a formal private club, which we later found out is entirely wheelchair inaccessibile. Mum is, of course, absolutely distraught. This was, for all intents and purposes, her legal son for a year and a half, and they have never stopped being close. And now, she can't be there at one of the most important birthdays of his life. She's spent every day since she found out crying, and I'm just absolutely furious. At best, it's stupidly negligent, and at worse, a deliberate decision to keep mum away. Hailey has a high opinion of Megan, but that's because she's unaware of just how awful she was for so many years, and it's an absolute kick in the gut that the woman who treated them so awfully for so many years gets to attend, while my mother can't.

She doesn't want me to say anything, but I'm absolutely screaming with rage. It's disgustingly unfair, and I want to let Hailey know just how awful this is. Simon's completely unaware of this, and I don't know how he'd react knowing that my mum wants to come but can't, based on a decision made by his fiancée. I'm scared it would cause tension between us, and between them. But equally, my mum raised him far more than Megan. Megan provided a roof, mum provided them with every ounce of love and care they ever got from a motherly figure. Simon and his brother haven't spoken to their biological mother in nearly ten years, so that isn't a consideration.

So, would I be the a-hole if I messaged Hailey and told her what she's done, and see if she is willing to make any adjustments or apologies? It would mean going against mum's wishes, but she's only doing that because she doesn't want them to know how upset she is. I've heard her sobbing her heart out, and I'm so furious that Hailey just didn't think or bother to check.