Gentle touch in dark is sexy (4)
I believe the answer is:
kiss
'gentle touch' is the definition.
(to kiss is to touch or brush slightly)
'in dark is sexy' is the wordplay.
'in' says the answer is hidden in the clue.
'KISS' is hidden within 'dark is sexy'.
(Other definitions for kiss that I've seen before include "Embrace" , "Snog" , "Eg, smacker, peck" , "Amorous greeting" , "Press the lips against" .)