Example : Awkward (or embarrassing or difficult) moments in the discussion.
An awkward pause followed his remark.
A sticky question.
In the unenviable position of resorting to an act he had planned to save for the climax of the campaign.

Synonyms : awkward, sticky, unenviable

Example : The embarrassing moment when she found her petticoat down around her ankles.
It was mortifying to know he had heard every word.

Synonyms : mortifying