Get sex partner on top (8)
I believe the answer is:
pullover
'top' is the definition.
(I know that pullover is a type of top)
'get sex partner on' is the wordplay.
'get sex partner' becomes 'pull' (pull can mean to attract someone for sex).
'on' becomes 'over' (I've seen this in other clues).
'pull'+'over'='PULLOVER'
(Other definitions for pullover that I've seen before include "Go to side of road" , "top gear?" , "Sweater or jumper" , "Woolly" , "Jersey" .)