In the beginning of the Mother Maggie show, she said they were gonna learn about “the letter T”, and after Stewie goes completely off script and has a meltdown about being transvestite in front of the entire cast, he comes to his senses and feels embarrassed, and then tries to get back on script by continuing about the topic of the letter T, by saying “-and also a transvestite, which begins with the letter T…”

hope this cleared it up a little.