"busted" or "why jay has a milk jug with his name on it"

So last night I totally caught Jay....And I was not even sneaking up on him. Just walking into the kitchen. But by his reaction, the jump, the look on his face, the sound, then the next look, then the comment, he knew he was caught doing something that he did not plan on me seeing. Or anybody else for that matter.
He had been saying he was so thirsty, and I dont know if he was expecting me to get him something to drink, but I did not. The mind reader was just not working last night. He left the room, and I shortly followed. Not to follow him, but to go get water for the iron. He obviously did not expect me to come walking around the corner at the exact moment that he was chugging from the milk jug. He jumped and almost lost the milk he had just chugged. I wish I had a photo of the expression on his face. Priceless. It was a mixture of emotion. Not very often is Jay speechless, or left trying to explain himself. It was just so funny. All I could say was " you are so busted"- and then I grabbed a sharpie marker and wrote his name on the jug. His comment to the kids in the morning when they asked why Dad had his own jug of milk?
" I thought that I would finish off the last bit of milk, and there was more in the jug than I thought"
Hmmmm I wonder how often he takes a quick swig from the jug!
AND I wonder how soon my kids will start doing their own swigging.
OR actually I should say, I wonder when I will catch them doing their swigging?
Maybe what I will do is just label my own milk jug for me, and everyone else can do what they want with the other jugs.