How to join a Minecraft game on the Xbox 360?

I don't mean with Xbox Live. I have two controllers and a friend wants to come over and play with me but I can't get the controller to join the game. I've never had any problems before, usually you just hit the start button. After I got this one update, it stopped working so I figured it was just a glitch or something, but I just got another update yesterday and it's still not working. Does anyone else have this problem? I've tried pretty much every button but it's not joining. I also know it's not my controller because multiplayer worked just fine in another game. Please, please, please help!