Jane prentiss so effectively impersonating Martin over text clearly means one of three things:

-Martin didn’t text very much so it’d be hard to judge whether it was his typing voice or not. (unlikely)

-Martin texts in such an unpredictable way that such a change of tone wouldn’t be weird. (possible)

-OR, Jane Prentiss scrolled through all his texts giggling and kicking her legs at his pitiful yearning, and copied him like a teenager role-playing their favourite fictional queer. (most likely)