[She catches the faint wary tone in his voice and kisses his cheek.]

Sure, why not? It might be fun to look at some stuff we can use together.

[She says reassuringly, trying to emphasize the word 'together' so that he knows that anything they buy will be used as a pair and not just as some kind of replacement for him.]

Oh! You know what, if you're worried about over sensitivity we can look at cock rings maybe? Or some kind of lube that numbs you a bit.