Have we considered the fact that I might just not care enough about a t-shirt to put up with this nonsense?

Let's act our ages - yes, both of us.  I acknowledge the chance that I may have acted childish more than once recently.

I thought a little distance, considering our bickering this past week, might be wise, but maybe I was wrong?

You have a phone.  I have a phone. 

I think we've always been able to talk, even when we hated each other.

So, if there is an issue, why not try conversation instead of holding a t-shirt hostage?