[Cindax]

Originally Posted by DextrousWeevil

I think I've found the answer to my own question Am I able to transfer DLC with my friend without transferring licenses witha USB? - Xbox.com

Indeed that is the correct information and here is a little more for clarity.

DLC is linked to both the Account and Console.
The account that pays for the dlc can download and play it on any console.
The original console that the dlc was payed for and first downloaded on; anyone can use that dlc.

It can get a little tricky with console licenses (needing to be re-validated or re-downloaded) but in theory if you take the time to buy all your dlc on a friends console you will both be able to make use of it. I have done this with my kids console.