post-sequitur

While a non sequitur is a comment which does not logically follow the preceding comment, and a pre-sequitur is a comment relating to something mentioned much earlier in a conversation, a post-sequitur follows something yet to be said.

Compared with non sequiturs and pre-sequiturs, genuine post-sequiturs are rare, as most Americans find them immoral.

Jack: Hey there, sweet thang.
Jan: Sure, I'd love to.
Jack: Would you like to go out for a drink? Wait, what?
Jan: Hells yeah it was!
Jack: Was that some kind of post-sequitur?
Jan: Fine, have it your way. Toodle-oo!
Jack: Away with thee or I shall do mur-rer-der-r-r!