How to disable the multiplayer feature for Minecraft?

My dad will only let me play Minecraft if he is positive I can't play multiplayer whatsoever. Does anyone have a way I could turn off multiplayer or block Minecraft from using Internet completley?
Please RSVP As soon as possible!

I don't believe you can, unless you disable the internet connection to your computer first.

I think that if you block minecraft.net with parental control you will not be able to go online. At least in my school it is like that because I can't access minecraft.net and I can't connect to the minecraft servers.