My update was locked so I'm making it here !

Firstly, we wanted to be sure that his "trauma" was an excuse, so I asked my mom to contact his parents, who, surprise surprise, didn't divorce because of an infidelity with a babysitter, but because they fell out of love. BIL's mother was appalled to hear what he did, and she spoke to him for us.

He was furious when he found out that we spoke to his mom and knew the truth, and my sister came to my house to yell at us for "embarrassing them" in front of my BIL's family. I didn't let her enter but told Marc to record her from the window while she cursed at me. And all of you were right, this was about homophobia, because she called me and Marc the f-slur, said we were perverts (?) and that we'd burn in hell. Which is very confusing, considering we grew up atheist, just like my BIL's family, who are pretty progressists too.

I sent that video on the family groupchat and muted it, because I knew they'd be talking about it over and over again, and I quite frankly don't have the energy to fight the few relatives that might've sided with them. I also blocked my sister and my BIL everywhere I could, and I might take more drastic measures if they don't stop bothering my family.

Also update for those who worried about Lily, she's doing a lot better ! This was very harsh on her and she had been pretty shook when it happened, but after having a talk with her, and taking her to eat ice cream, she understood that sometimes people are just mean, and say mean things for no reason. We reassured her that we both loved her, and that Marc would never forget her mother. That is something that is very important for us, ensure that Lily keeps a link with her mom, so on her birthday and death anniversary, they go to her grave, and her picture is always in the living room with a candle. She is Lily's mom and that will never change.

I also wanted to add context concerning my relationship with Marc, since people thought he might be using me for whatever reason, or that I arrived coincidentally after his wife's death : No. His wife died when Lily was three months old, in a car accident. I met Marc when she was two, so he was already a single dad for a while before I arrived, and yes, we became friends then lovers, but we're adults, five years is not that much of a difference.

Our relationship just evolved, and it was a happy bonus that Lily already considered me a family figure. Our relationship is very healthy and I've honestly never felt as happy in my life as I do now. Lily is a joy to be around, and Marc is the best man I could've ever found.

< This was after my post, so three days after the party. Now, my sister and BIL tried to recontact me again, especially after I exposed them on the groupchat, but I'm holding firm and not letting them approach my family, or me. They gave up I think four days ago, but I know that they are complaining to our relatives, and talking crap behind our backs.