How is the SD going to "find a place" when she won't work? And, if your wife really believes her daughter will find a place and this will only be temporary, why would she be concerned about her grandchild living in a basement? Shouldn't SD be on her own by the time the baby comes?

This will not be temporary. Tell your wife to direct her daughter to social services and to start the paperwork to serve the father for child support. The courts will require a DNA test once the baby is born and child support will be ordered.

I am not one to encourage living off of the government (as my own SD does) but it is better than the alternative (living with us).

I understand that your wife wants to help her daughter but it is not as if she is homeless. And, she should not just discount your input, in your own home.

No way in h@ll anybody moves into my house without my input. You and your wife need to have a discussion, a calm one if possible, and come up with alternatives.

I get that she's concerned for her daughter and grandchild. But there are alternatives to moving in with you, which has been a disaster in the past it sounds like. Add a newborn to the mix, and it's worse. That's reality, and no point ignoring reality hoping that the daughter will suddenly figure it out and start acting like an adult.

If you leave, take your children with you. Posession, aka status quo, is important in custody.  

SD is old enough to get a job or get on assistance - your children aren't.

Inform your wife that SD is NOT moving in and if she insists on helping SD, let DW move out and join SD until SD gets on her feet.   You are making a choice of two small children who need a positive environment vs. a dead beat who will be not only be a bad example but will be taking away funds from the children.  Say, "No" and tell DW you mean it.  Fight for your children.

It sounds as though SD already has a safe place to live (her grandparents' basement).  I am a firm believer in following through with what I say.  You told your wife that you did not want SD to move into your home.She disregarded your wishes.  You have told your wife that if she moves SD in that you will move out.  I say, follow through with that. Shift your focus to your small children and decide whether it would be best for them to live with your wife or with you. 

Good Grief....IF this was my own bio---here is what I would say....I kid you not. One part is actually based on a true story..

Congratulations...on your pregnancy. Who is the Father?  Now, Grab your bag because WE are going to social services. There you can sign up for WIC, welfare, food stamps and housing. YOU need to get a job too. Walmart, Wendy's YOU pick. Macy's?

PS...NOPE you are not moving into our home. Your an adult now act like one. Also before you say it, kindly allow  me clear a few things up for you. They are:

If you ever attempt to tell me I will not see our Grandchild ever again IF we DO NOT 1. allow you to move in. 2. Babysit. 3. give you money ....trust me I will say OK THEN and walk away and not see you OR our Grandchild again.

Lets go look at baby stuff after Social Services...I will treat you to lunch too.

Ugh, what an awful situation.

I'm not sure what difference it makes if there are other children at the grandparents' house. I don't buy that excuse nor that the basement is not good enough for SD and baby if SD has already been living there.

Offer some other options: If the basement isn't nice enough for SD, why not chip in to dress it up? It's nicer than a shelter would be. Chip in for an apartment for a year. Keep offering options that will keep SD out of your house. When your wife keeps saying no, and she will, it's time to pack up and go. But at least you know you offered alternatives and your wife was unwilling to compromise.

This will not be the last baby for SD. She is only getting started. If there have been no consequences for her bad behavior so far, and she gets a bigger prize for her worst behavior of all (reproducing and ruining a kid's life), that will only encourage her to keep breeding.

I'm sorry you're going through this. Your firm decision to move out at the start should be a lesson to the rest of us who compromise, try to make it work, bend over backward and eventually end up leaving anyway -- sooner is better than later.

If you go, take your kids with you. Better yet call a locksmith to rekey the locks and inform DW that if she prioritizes the toxic breeder over your shared young children that DW will be moving into her mommies basement with her breeder waste of skind crotch nugget. 

Your young children should not be exposed to this toxic out of wedlock breeding etitlement queen wannabe adult or your wife for that matter. At least not if your wife is willing to jeopardize the wellbeing of her minor children to waste yet another effort supporting her prior relationship toxic crotch dropping.

Your wife is choosing  the toxic SD over not only you but also over her/your young children.

If your SD-28 were special needs my thoughts would be somewhat different. That she is a voluntary  breeder who has chosen to not support herself makes her a write off IMHO.  That  your DW appears to be willing to sacrifice your children on the alter of guilt she has regarding her elder spawn is alarming.

Good luck. Take care of your babies.

Run! Run fast! The sad part is SD will never move out once she moves in because of her enabling delusional BIO. Mom will never make her leave. I will never tolerate having an infant in my home that is not my own.  

Your wife is more intrested in saving her daughter than your marriage; she is clearly letting you know how you rank.

I know it's going to hurt like hell to not live the life you are used to with your children, but everything will work out.  Your wife will get every bit of the life she is signing up for with her daughter.

SD will wreak havoc on the entire house with her entitled behavior. You will literally be takig care of her adult child and the grandchild if you stay. No way in hell would I mentally or emotionally subject myself to your wife's adult garbage spawn!

Be brave, whatever you do protect your mental health and your emotions for the sake of your children.

Good luck!