Land's politician admitting slip before Congress (9)
I believe the answer is:
territory
'land's' is the definition.
(thesaurus)
'politician admitting slip before congress' is the wordplay.
'politician' becomes 'tory' (I've seen this before**).
'admitting' means one lot of letters goes inside another.
'slip' becomes 'err' (I've seen this before).
'before' says to put letters next to each other.
'congress' becomes 'it' (congress can mean sex).
'err'+'it'='errit'
'tory' placed around 'errit' is 'TERRITORY'.
(Other definitions for territory that I've seen before include "Region marked off for some purpose" , "One's own area, land" , "province" , "ground" , "Geographical region" .)