u/Apart-Moment-3227

As some back story I'm 27 and have a 1 year old son and I ended up talking to and getting into a relationship with a 35 year old and everything was great we have been together for almost a year and we have sorta merged our families. Now for what I need advice on recently was looking for a bigger apartment and seeing how everything is super high rent I decided to buy 2 acres and just build our own house since I have the skills to but recently my girlfriend has been telling me that she doesn't like that I consider my son's mother's feeling and don't really argue with her in front of my son but to me I was only doing that so he wouldn't ever have to see me and his mom arguing because mine and her problems are ours and he shouldn't be in the middle of that but then my girlfriend says she wants her baby father to move in with us after I build our house and mind you she has said that they are toxic and always fighting and that he's never been apart of his kids lives but she still keeps bringing up that she wants him to move in with us since he's homeless and in his car which I think shouldn't be my problem especially if I would then have to provide for our 3 kids ( my 1yr her 1yr and her 2yr) her and now her baby daddy and i dont know how to approach it or even bring it up even though my intention isnt to keep her kids from their bio dad. how do i even approach this or bring it up?