Moving in together: when your new partner meets your kids (and your ex finds out)
A new partner moving in changes more than your living room. What actually shifts legally, how to pace introducing them to the kids, and how to tell your ex without starting a war.
Nobody warns you that starting again can feel more complicated than the separation. There's no form for it and no lawyer walks you through it. But get the timing wrong, or the way your ex finds out, and it can undo months of hard-won stability for your kids.
This isn't about whether you're allowed to move on. You are. It's about doing the relational and practical parts in an order that protects what you've built. There are three stages, and each has its own rules: the kids meeting your partner, overnight stays, and moving in.
Stage one: meeting
There's no universal number of months that makes this safe. Three things matter more than the calendar. Is the relationship stable and likely to last, not still finding its feet. Have you run your own household long enough that your kids have a settled rhythm with you. And can you introduce this person as someone in your life, rather than announcing a role for them.
Younger kids generally adjust best to a low-key introduction with no big buildup: a park, a meal, a short visit. Teenagers often do better with some say in the timing and pace, even if the final call is yours. Either way, keep early meetings short and don't make them the main event of the weekend.
Stage two: overnights
Check your parenting plan or orders first. Some include a clause requiring you to tell your ex before a new partner stays overnight when the kids are there, or before anyone moves in. Read yours before you act, not after. If there's no clause, you're not legally required to ask. A heads-up is still usually smart, for reasons covered below.
Stage three: moving in
This is where most of the practical and legal changes sit.
Centrelink. If you receive Family Tax Benefit, Parenting Payment, rent assistance or other payments, a new relationship can change them, because your partner's income and circumstances count once you're a couple. Services Australia's rule is that you tell them of a change in circumstances within 14 days, and you can be treated as a couple without living together. Get this wrong and you can end up with a debt. The Centrelink article has the detail.
Child support. A new partner moving in doesn't change your assessment on its own. The formula runs on your income and your care percentage, not your relationship status. You can check yours in the child support calculator.
Property. This one catches people. A de facto relationship can give your new partner rights to make a property claim against you under the Family Law Act, generally once you've lived together for two years, or if you have a child together, or in limited cases where there's a substantial contribution. If you own a home or have assets you want to protect, a financial agreement is the usual way to set the terms up front. It's worth a conversation with a lawyer before you merge finances, and especially if your property settlement with your ex isn't finalised. If it isn't, tell your lawyer a partner is moving in.
The household admin. If someone's moving in, your lease may need updating to add them as an occupant. Your contents insurance may not cover their belongings unless they're named. Update the emergency contacts and authorised pickup list at school if this person will be doing pickups. Review your will and super beneficiaries, which often still name your ex. Note the date they moved in, in Atlas Records or wherever you keep records. You'll want the date for Centrelink and for any later de facto timeline.
Telling your ex without starting a war
This is usually the part people dread most, and it's where the BIFF method earns its keep: brief, informative, firm, friendly. You're not asking permission, unless your plan or orders say you must. You're giving a courtesy heads-up so your ex isn't blindsided by a child's offhand comment.
The order that tends to work: decide with your partner what's happening and when, send your ex a short message a few days before the kids meet your partner or before anything changes, then tell the kids yourself. That way, the kids hear it from you rather than from the grapevine, and your ex hears it from you rather than from the kids.
Something like: "Wanted to let you know [name] will be around more from next month, including some overnight stays when the kids are with me. Happy to talk through any logistics." Factual, short, no debate invited. If your ex escalates, that's information about them, not a sign you did something wrong. There's a ready-made version in Atlas Scripts if you'd rather start from a template.
Don't ask the kids to carry the message. And keep the first few weeks boring: same routines, same handovers, same time alone with you. The goal isn't a perfect reaction from anyone. It's that your kids' week looks as stable on the day your partner moves in as it did the week before.
If your partner has kids too, read the blended-family article before you set a move-in date.
This article is general information about Australian law and services as at October 2026. It isn't legal, financial or medical advice and doesn't consider your circumstances. Rules and figures change, so check the linked sources. For advice on your situation, talk to a family lawyer, Legal Aid in your state, or the Family Relationship Advice Line on 1800 050 321. If you're worried about your safety, call 1800RESPECT (1800 737 732) or 000.