Diego is bad at waiting, but he tries. It's easier, when she trips over her words in a way too viscerally familiar to him, to be patient. The way he thinks he remembers her being with him, before, when they were kids and he got stuck on certain words.

That isn't to say he's replaced by a more understanding person, completely, though, because all that he comes up with to say when she finally gets it all out is:

"Can't you just get another one?" He can't fathom going back just for that.