Slip back, as kinky pleasure not suitable for everyone (7)
I believe the answer is:
relapse
'slip back' is the definition.
(I've seen this in another clue)
'kinky pleasure not suitable for everyone' is the wordplay.
'kinky' is an anagram indicator.
'not' indicates named letters should be taken away.
'suitable for everyone' becomes 'U' (as in a Universal film certificate).
'pleasure' with 'u' taken away is 'pleasre'.
'pleasre' with letters rearranged gives 'RELAPSE'.
'as' is the link.
(Other definitions for relapse that I've seen before include "Backsliding" , "Medical setback" , "setback in health terms" , "Decline" , "Downturn in health (after improvement)" .)