I think it just depends on what you can give and what you want. I am married to N, he has a GF J. There is no way N can divide his time 50/50 with her. Right now she lives with N's mom so N wont go over there but she is welcome to spend the night here while im at work (since N's mom is there with her kids) and she even will stay the occasional weekend night when I am here.
When she moves she will be working weekends so she will not be available on the weekends at all. She and I have decided we will do a group movie night on mondays with the 3 of us like we use to and Thur will be the night a week that N can spend the night there if he chooses to (sound like that's not something he really want to do though) Im at work tue and wed overnight so he cant spend the night there those nights because we have kids at home and she wont be able to spend the night here anymore because she will have her kids at home and they have school. during the summer she can bring her kids over here to spend the night during the week days like she use to.
I dont have any other partners but when I do get one I also will be available to spend the night with them if they are able to host one night a week. If they cant host I will probably opt not to do sleep overs.