Dear Prudence

Help! My Boyfriend Wants His Ex to Come Live With Us.

Dear Prudence answers more of your questions—only for Slate Plus members.

A pregnant woman and her 5-year-old son standing in a doorway.
Photo illustration by Slate. Photo by Getty Images Plus.

Every week, Dear Prudence answers additional questions from readers, just for Slate Plus members.

Q. Can’t move in: My boyfriend lost his job and has moved in with me, since I own my own home and rent prices have risen sky-high. We have been talking about marriage. He shares custody of his 5-year-old son with his ex. We have a room set up for him. The ex is pregnant and broke up with her boyfriend. Her landlord is not renewing the lease, and she can’t find another place in the city. Her parents live out of state. She wants to move into my house just until she gets “back on her feet.” I said hell no. I don’t have strong feelings about her, but a situation like that can only go south.

My boyfriend is upset with me for not even considering it. I told him I am happy if his son moves in with us full time but we need boundaries between our family and his ex’s. She and her new baby are not our problem, to put it bluntly. He said I am costing his son his mother. I told him it wasn’t fair and that he could always move to where the grandparents lived if he’s so concerned. He can’t put this all on me. All this has shaken me. I love this man and his son, but I am wondering about what happens if we break up? Should I do it now? Am I panicking over nothing? I only dated casually before this.

A: This certainly isn’t “nothing,” so you can let go of that fear at least. Obviously your boyfriend’s ex is in a difficult situation—you all are—but it’s perfectly reasonable to say, “I’m not comfortable with the idea of living with your ex,” especially when the proposed time frame is “until she gets ‘back on her feet,’ ” which is difficult to write into a lease and could take anywhere from a few months to a few years. The fact that neither your boyfriend nor his ex can afford rent in your city right now is terrible, but you’re not to blame for the housing market. Nor are you being unreasonably cruel by saying, “The three of us living and co-parenting two children with three different parents is not a sustainable solution.”

You’re right to be shaken by your boyfriend’s assertion that you are “costing his son his mother” because it’s totally inappropriate for your boyfriend to put you in that position of responsibility. I don’t think you have to dump him tomorrow, but you should certainly share your concerns with him, reiterate that you are not available to live together as a threesome, and encourage him to come up with alternatives for his co-parent and his child.