Pleasure-seeking male teacher is married (8)
I believe the answer is:
hedonism
'pleasure-seeking' is the definition.
(hedonism is the pursuit of pleasure)
'male teacher is married' is the wordplay.
'male' becomes 'he' (he refers to a man).
'teacher' becomes 'don' (don is a kind of teacher).
'married' becomes 'm'.
'he'+'don'+'is'+'m'='HEDONISM'
(Other definitions for hedonism that I've seen before include "The pusuit of pleasure as life's greatest good" , "Belief that pleasure is the highest good" , "Doctrine that pleasure is the highest good" , "The pursuit of happiness as a matter of principle" , "The belief that pleasure is the chief good in life" .)