When you are already stuck in a particular problematic situation and there is a high risk of being discovered by third parties and it could lead you to embarassment, imprisonment, a smack-around-the-head, grounding, divorce, a severe belt-beating etc. Bonnie Situations can be a psychological burden as you are trying to get out of the situation as quickly as possible before you are discovered - a kinda race-against-the-clock. A Bonnie Situation is more aptly used when a husband is about to be found out doing something wrong by his wife. Only the very focused and quick thinking macks can cooly arise from a Bonnie Situation.
Dude1: Daaamn hombre! Your homegrown marijuana harvest is good this year.
Dude2: Is that your parents car pulling up in the drive way?
Dude1: Shit! Quick! Open the windows, fetch the deodarant spray.
Dude2: We got ourselves a Bonnie Situtation.
Jimmie: Now don't you understand that if Bonnie comes home and finds a dead body in her house, I'm gonna get divorced. (....)
Jules: You got to appreciate what an explosive element this Bonnie situation is. If she comes home from a hard day's work and finds a bunch of gangsters doin' a bunch of gansta shit in her kitchen, ain't no tellin' what she's apt to do.
(From the movie, Pulp Fiction)