Argument between my boyfriend and I?

It's a bit offending that he feels he needs to "get the same amount of time as you" since he made it seem like it didn't matter. This is one of those types of arguments that is going to happen until he evolves a sense of giving just to give. It's probably not just with you that he feels this way. Many people say they are ok with letting somebody use their stuff, but in the end, they usually want it back or feel like you owe them. He wants to make things "even" but he doesn't realize that it isn't some business deal. This is not really something that is easy to explain to people that don't already feel this way, so just tell him you didn't think you guys were keeping track of how long you each had the Xbox.