An empty question/answer leaves much space for comments. Like this:
A: Do you mean
OP: @A Yeah, let me fix that.
OP: @A just fixed the question.
A: @OP Yeah, cool.
OP: @A Thanks for letting me know.
A: @OP No problem. Keep up the good work!
OP: @A will do!
Once the question is edited, let's try to remember to delete comments (and keep them to a minimum in the first place). If people come and have to click [12 more comments] just to find long conversations of the above sort, it costs everybody time and it just crowds the site.
For friendly chats, there's always our chatroom. (Leaving a message in the chatroom with
@username also pings the user with that name.)