Love affair makes Scottish reel (5)
I believe the answer is:
fling
I believe this is a double definition.
'love affair' is the first definition.
(I've seen this in other clues)
'scottish reel' is the second definition.
(Highland fling is a Scottish reel or dance)
'makes' acts as a link.
(Other definitions for fling that I've seen before include "knees-up at 8 [HIGHLAND GAMES]" , "Hurl" , "Spell of indulgence" , "See 7" , "Highland dance - spell of way-out behaviour" .)