How to share iTunes music from my iPhone 5 with another iPhone 5?

My wife and I both have an iPhone 5 but only my wife buys iTunes cards and stores music and books etc we're wondering is it possible to easily transfer music from my wife's iPhone 5 iTunes account onto my iPhone without both of us losing anything

Download an app called bump.

Maybe if you use the same computer and have the same iTunes Library on the computer. If you use the same computer then when you plug in your wife's phone it will try and sync all the music from the library to her phone unless you've changed the setting to only a few songs or what have you. Then if you plug in your phone you should be able to do the same thing.