Do lovers without protection attack? (10)
I believe the answer is:
overcharge
'do' is the definition.
(do can mean to cheat someone of money)
'lovers without protection attack?' is the wordplay.
'without protection' says to take the centre (no outside letters).
'attack?' becomes 'charge' (charge is a kind of attack).
The centre of 'lovers' is 'over'.
'over'+'charge'='OVERCHARGE'
(Other definitions for overcharge that I've seen before include "Ask too much" , "leave phone plugged in unduly long!" , "Rip off" , "rook" , "Demand too high a price" .)