Dance: couple’s favourite returns (3-4)
I believe the answer is:
two-step
'dance' is the definition.
(two-step is a kind of dance)
'couples favourite returns' is the subsidiary indication.
'couples' becomes 'twos' (I've seen this before).
'favourite' becomes 'pet' ('pet' can be a synonym of 'favourite').
'returns' says the letters should be written in reverse.
'pet' back-to-front is 'tep'.
'twos'+'tep'='twostep'
(Other definitions for two-step that I've seen before include "Old-time dance in duple time" , "Old time dance" , "Wet pots (anag.)" , "Sot wept doing ballroom dance" , "Dance, maybe military" .)