Supports arrangement of date with current unwelcome controller (4-4,6)
I believe the answer is:
back-seat driver
'unwelcome controller' is the definition.
(someone who gives unwanted advice)
'supports arrangement of date with current' is the wordplay.
'supports' becomes 'backs' (backing is a kind of supporting).
'arrangement of' indicates an anagram.
'with' is a charade indicator (letters next to each other).
'current' becomes 'river' (I've seen this before).
'date' is an anagram of 'eatd'.
'backs'+'eatd'+'river'='BACK-SEAT DRIVER'
(Another definition for back-seat driver that I've seen is " one offering advice".)