The mod basically uses one PC as a server, so you can all join the same game. This is about as close as we can hope to getting a Sims 4 multiplayer mode, for the time being at least. You can check ...

it would make sense if players interacted with each other in careers throughout Project Rene’s gameplay, considering EA and Maxis’ heavy emphasis on multiplayer interaction.

While not much has been revealed about the title, Project Rene should use preexisting locations to expand its multiplayer ...

If you’re curious whether The Sims 4 features multiplayer ... this mod only works on PC, which means that players on consoles have no way to play online with others. Bummer.