splitscreen

My question is basically in the title. I would like to host my farm for the new splitscreen mode and still use my controller, while my friend would like to use my mouse and keyboard every once in a while as my farmhand. How do I set it up?

Few days in on new file. No mods. After going to bed the level up screen appears. I can still move my mouse. But can not proceed. Does not appear to be frozen, graphics are still chaning (little twinkled around level up banner). Second player is just black screen. Please help