I don't know where this originated but iv'e been hearing it often. It is used when people get hushed or "hush mode".
A Stale Daddy is a face you make after someone hoed your life like-
A stale daddy is another form of hush mode
Person A- " You smell like tortilla chips and stale beans!"
Person B- " I..... Bitch i_i"
Random Background person-" I Sense a Stale-daddy!!!!"
Person A- "Yo mamma so fat she stupid!"
Person B- *Cricket cricket* i_i
(scenario is in a school and both people stand up and argue)
Person A- " Wit yo ol' retard butt"
Person B- "I kno u ain't talkin wit yo Dirty Ass"
Person A- *sits down* i_i
Person C- " DAT NIGGA GAWT A STALE-DADDY!!"
Person A- "Shut up bitch before i whoop your ass"
Person B- i_i
Person C- "Now that's the biggest Stale-Daddy i ever seen"