Hot desire in couple (5)
I believe the answer is:
hitch
'couple' is the definition.
(thesaurus)
'hot desire' is the wordplay.
'hot' becomes 'h'.
'desire' becomes 'itch' (itch is a kind of desire).
'h'+'itch'='HITCH'
'in' is the link.
(Other definitions for hitch that I've seen before include "To travel without paying" , "unite" , "knot" , "Hindrance" , "Pull up" .)