n. phr. , informal An unpleasant part of a pleasant thing; something small that spoils your fun. We had a lot of fun at the beach; the only fly in the ointment was George's cutting his foot on a piece of glass. Your new job sounds too good to be true interesting work, high pay, short hours. Isn't there any fly in the ointment?
FLY IN THE OINTMENT
Meaning of FLY IN THE OINTMENT in English
American idioms English vocabulary. Английский словарь американских идиом. 2012