Fuming, mostly with northern man getting married for family space (6,4)
I believe the answer is:
living room
'family space' is the definition.
(room in a family home)
'fuming mostly with northern man getting married' is the wordplay.
'fuming' becomes 'livid' (I've seen this before).
'mostly' means to remove the last letter.
'with' says to put letters next to each other.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'man getting married' becomes 'groom' (a groom is about to get married).
'livid' with its last letter taken away is 'livi'.
'livi'+'n'+'groom'='LIVING-ROOM'
'for' is the link.
(Other definitions for living room that I've seen before include "Area in home for relaxation" , "Home space" .)