This is the last survivor of one of many "Haven't heard anything like that since Grandma (Grandpa) ..."
expressions that used to mean someone was overdramatizing their problems. Implied the person commented on was acting like a whiny old person. "Haven't heard anything like that since Granny got her tit caught in the wringer" was what you'd say when, e.g., a coworkers spent the morning
complaining about someone having taken the last cup of coffee and not making a
fresh pot.
"And everyone forgot to tell me that Awards Day is next week! Why doesn't anyone ever tell me? Doesn't anyone care ...." etc.
(whispered to friend) "Haven't heard anything like that since Granny caught her tit in a wringer."
(Alternatives that once were common) "Haven't heard anything like that since someone put a
cherry bomb in Grandpa's truss."
"Haven't heard anything like that since Granny sat on the
toilet plunger."
"Haven't heard anything like that since Grandpa got a
turd stuck sideways."