Romance; occasion (6)
I believe the answer is:
affair
I believe this clue is a double definition.
'romance' is the first definition.
(affair can mean a romantic fling)
'occasion' is the second definition.
(synonyms)
(Other definitions for affair that I've seen before include "Sexual liaison - concern" , "A fling (or something more serious?)" , "Romantic relationship, perhaps illicit" , "Clandestine romance" , "Liaison or intrigue" .)