Massage area around member: you need a partner to do this (5)
I believe the answer is:
rumba
'a partner to do this' is the definition.
The definition suggests a singular noun which matches the answer.
'massage area around member' is the wordplay.
'massage' becomes 'rub' (I've seen this before).
'area' becomes 'a' (maths abbreviation).
'around' means one lot of letters goes inside another.
'member' becomes 'm'.
'rub'+'a'='ruba'
'ruba' enclosing 'm' is 'RUMBA'.
'you need' acts as a link.
Can you help me to learn more?
(Other definitions for rumba that I've seen before include "South American dance" , "Ballroom dance of Cuban origin" , "Dance originating in Cuba" , "Cuban folk dance" , "one's on the floor for it" .)