he could start a single payer game and you could join him as long as you are on the same lan network you goto after he starts his game Multiplayer then in that option at the bottom of the screen you will see Connect to IP click that and enter the local ip address of your partners computer it should look something like this 192.168.1.104 or 10.1.1.5 this is not his ip just a example after that click connect and you should be able to join his world
