AITAH for getting upset that my father-in-law stayed in my house the night before his mother’s funeral?

I (25f) and my fiance (25m) have known eachother since we were 9 years old. We’ve been together for 6 years and have been through ALOT together. A little context, his family has a long history of drug problems and toxic generational behaviors. His father abandoned him at 15 years old and moved 3 and a half hours away. About a month ago my fiancés grandmother passed away. She had been in a nursing home for years and no one really checked on her much. We had all planned a way for his father to come down here and had a place for him to stay. Me and my fiancé discussed him staying with us and we decided against it, or so I thought. We originally decided he would stay with his brother. Later that night, I got a call from him stating that he was almost home and that he wasn’t taking his dad to his brother’s house. He said he was 5 minutes away and that I had no say in whether he stays at our house or not because it’s “his family”. I told him my concerns and that I wasn’t okay with drugs on the house and that I did not trust him. We got into an argument where he said that I should be more understanding because his grandma just passed away, and that was his mom, and to have a little empathy. I understood his dilemma. I know his dad said he didn’t want to go down to his other son’s house. I don’t know the reason but I have a feeling it had something to do with the other son not putting up with any kind of bullshit and my fiancé is very much a pushover when it comes to his family. The whole situation made me feel steamrolled over. The lack of respect is what hurt me the most. I love my fiancé and his family. I’ve known them for as long as I can remember, but I also know what kind of people they are and I can love them without letting them into my home. Recently, my father-in-law has resorted to posting mean posts about, not only me and my fiancé, but his other son as well. He tried saying that I wouldn’t let him in my house (not true) and that he was outside for hours (more like 5 minutes) I definitely feel like an asshole because I argued with my fiancé about this the night before the funeral, but I should be able to have a say in who is allowed in our household, especially if it makes me uncomfortable in my own home. So, AITAH?

Thank you everyone for your opinions. I’ve been wracking my brain on if I’m the AH or not. I appreciate any future judgements!

Edit to clarify- his dad only stayed one night which is why my fiancé didn’t think it was a big deal