Giving affection, having a close relationship (4,2,5)
I believe the answer is:
hand-in-glove
'having a close relationship' is the definition.
(hand-in-glove means working together)
'giving affection' is the wordplay.
'giving' becomes 'handing' ('hand' can be a synonym of 'give').
'affection' becomes 'love' (I've seen this before).
'handing'+'love'='HAND-IN-GLOVE'
(Other definitions for hand-in-glove that I've seen before include "Closely associated (in nefarious activity)" , "In cahoots" , "Complicit" .)