I’m posting on behalf of a friend. His now ex wife started a relationship with a mutual friend, and their sons best friends father.
After she left the family home she had limited interest in seeing the children, instead spending time with her new partner. During this period she would have occasional sleepovers with the children at her parents.
She has now set up home in a very small 2 bed house, and the despite agreeing in mediation to the contrary, her daughter’s and his son are all sleeping there together, with two of the children not even sleeping on beds.
Whilst this is not such a problem during holidays, we are concerned that they will now request over nights during the school week, and do not feel this is fair on them.
Mediation has been futile, as they agree on things, and then change their mind and have disregarded previous attempts at a parenting plan.
So who is the resident parent? Your friend I presume? You could block overnights during school weeks. You can give them advance notice of this. If they want to negotiate, that’s when you have to agree a proper plan with the issues you’re concerned about (I presume lack of proper beds on a school night?). Of course, such things are not legally binding, in which case it’s best to withhold school night sleepovers on that basis and if she disagrees, she can pay for a solicitor to have the conversation with you or take you to court. If they don’t have proper places to sleep they can stay there.
She’ll soon learn that the alternative to a discussion which can achieve results for both of you is a discussion she pays a lot for which can achieve the result you want.