Cover verse in song for two (5)
I believe the answer is:
duvet
'cover' is the definition.
(a duvet is a bed cover)
'verse in song for two' is the wordplay.
'verse' becomes 'v'.
'in' indicates putting letters inside.
'song for two' becomes 'duet' (I've seen this before).
'v' going into 'duet' is 'DUVET'.
(Other definitions for duvet that I've seen before include "Bed quilt" , "Continental quilt" , "Warm covering for bed" , "Type of quilt" , "Eiderdown" .)