Why?
 

Why is it if I buy a gallon of milk it will be still in my fridge 6 days later? But if I buy two half gallons, my wife and two kids drink both of them in 2 days?

Maybe the gallon jug is too heavy. :)

One of life's mysteries.

I bet your kids are drinking right from the half gallon carton, which is easier to do than drinking from a gallon jug.

I wish it was that easy. But my 3 year old isn't doing that. I really don't understand it. It happens every week. I have to go and get milk now. And right in the middle of the game. Isn't that always the way?

Save the half gallon cartons, buy a gallon of milk and pour them into the half gallon cartons.

Or just keep buying gallons so you never have to go in the middle of the game again to get some more.

...or man up and stop doing your wife's job for her.