My FI and I asked a friend of ours to move in with us back in June. She's a single parent (young) and was living with her parents. Her father is an alcoholic and beats up on her mom. She didnt want her daughter (now 2) raised around that. We understood and said she could move into our spare bedroom until she got her money together to get her own place. Her daughter is the same age as our son and since the father of her child passed, My FI has taken on the "uncle" roll with her. Also we could help eachother out. It all started fine until one night she had a guy stay over. Now, we didnt mind that. She's an adult and is paying rent . The problems were 1- she put her daughter in my son's room on the floor so this guy could spend the night. 2- her daughter woke up screaming and crying cause she's used to sleeping with her mom. That woke my son up which woke me up. She's in the room sleeping (we didnot know the guy was in the room at this time. We didnt even know he was in the HOUSE) I realized that when i looked out the window to see if her car was there cause i was trying to figure out why her daughter was in my son's room on the floor to begin with. I see his car, put 2 and 2 together and came up pissed. i get both kids quieted down and back to sleep (after knocking on her door and getting no response) the following morning, My FI gets up with the kids (she and the guy are still in the bedroom) as he is coming upstairs to tell me that he is going to the store to get eggs for breakfast, he hears the 2 of them having sex. NOT GOOD.
After the guy leaves, i talk to her and tell her that i dont appreciate her putting her child in my son's room on the floor, I dont appreciate having to get up with both kids cause her's woke up and woke mine up. I also informed her that i didnt appreciate the disrespect of her having sex when we are awake and in the house and when my son is awake. We dont do that and its not acceptable. she said she was sorry and she understood.
about a week later, We all go over to a friend's house. She leaves early and takes my son with her saying she is going home to lay down and will put the kids to bed. a couple of hours later, My fi and I come home to find the same guy's car parked out front. We go in the house, my son is in my bed and her daughter is in my sons room on the floor AGAIN. So, we again have the discussion about how this is UNACCPTABLE, DISRESPECTFUL and not going to happen again.
in addition to this, she was only cooking when he came over, we only asked her to pay 360 a month this wasnt being paid in a timely manner, and we were covering the rest of the bills (which had gone up since we now had another adult in the house) she was eating up all of our food. and would sleep all day on the weekends while we watched her daughter.
Finally, my FI blew up.. he told her what he thought and how disrespectful she was. She then said she was moving out. At this point, im not sure that i want her in my wedding anymore. My FI has made it perfectly clear that he would rather her not be in the wedding anymore.. Is it okay for me to "kick her out" (sorry i couldnt find a nicer way to put it)

When you are in love you cant fall asleep because reality is finally better than your dreams.
~ Dr Seuss