AIO for telling me best friend that her married boyfriend is not welcome in my home
I (45F) let me best friend (38F) and her 5-year-old daughter move into my house over 2 years ago when they needed a place to stay. It was supposed to be temporary but here we are nearly 3 years later.
Around Christmas time my best friend, we'll call her Amanda, was contacted by an old friend, , we'll call him Dave. They were friends around 15 years ago and according to Dave he has always been in love with Amanda, even though he has been married for 14 years and has 4 kids with his wife. This was all news to me until shortly after New Year and when Amanda came to me and told me that Dave's wife found out he was talking to Amanda, and also that his wife knew where we lived because Amanda stupidly sent Dave one of those iPhone map notifications that his wife saw on his ipad that was linked to his iphone. His wife then proceeded to contact Amanda via text and facebook asking her what kind of woman breaks up a family with four kids. This upset me as I do NOT want any scorned wives showing up at my home causing drama. I was also upset with Amanda for even getting mixed up in this mess and would never have thought she would have an affair with a married man. (Note to say that Dave is feeding her all these lines about how his wife is abusive to him their married has been over for a while but yet he won't file for divorce).
At that point I told Amanda that Dave would not be welcome in my home. She even had Dave on speakerphone that night so that he could explain how his wife wouldn't do anything to hurt us and that she was basically too stupid to read a map to find my house. I told them both that that meant nothing to me and reiterated again that I did not want Dave anywhere near my house. Never underestimate a woman scorned!
Fast forward to now ( 5 months later) Amanda doesn't talk to me about the situation because she knows I do not approve of her being "the other woman" in this whole mess. To my knowledge, Dave is still living with his wife and has not filed for divorce. At some point they stopped meeting but were still texting/calling each other. The other week she asked if Dave could come by so they could have a conversation and I again told her I don't want him in my house. Today, I found out she started meeting him again, outside the house. Honestly, I'm upset about the whole situation but mainly because my best friend can't see that she deserves more and is worth more than a man who is keeping her as a side piece. I also love her daughter (who I consider my niece) dearly and am upset that this is the example she is setting for her.
I'm I wrong for telling her Dave is not welcome here? I know she is a grown woman and can do what she wants but this is my home and I'm too old be getting mixed up in this immature nonsense.
I'm even contemplating telling her if she wants to continue messing around with him while he's married that she needs to find another place to stay because I feel like inevitably the drama will follow her home.
I'm not sure how to approach this with her without it turning into a confrontation.
Side note... Dave works for a well-known local church and Amanda is also heavily involved in the church we attend which makes this all even more ridiculous that they can even justify this affair. For people to claim to live a righteous life and preach to others about right and wrong when they clearly do whatever they want to do boggles my mind.