Resign, being unhappy at blue-eyed boy’s return? (4,4)
I believe the answer is:
step down
'resign' is the definition.
(I've seen this before)
'unhappy at blue-eyed boy's return?' is the wordplay.
'unhappy' becomes 'down' (I've seen this before).
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'blue-eyed boy's' becomes 'pet's' (both can mean someone treated as a favourite).
'return?' says the letters should be written backwards (I've seen 'returns' mean this).
'pets' written backwards gives 'step'.
'down' put after 'step' is 'STEP-DOWN'.
'being' acts as a link.
(Other definitions for step down that I've seen before include "Leave office" , "Get off one's soap-box" , "Resign from office" , "Withdraw from" , "decrease in output" .)