Love, as it happens, oily fruit (5)
I believe the answer is:
olive
'oily fruit' is the definition.
(as in olive oil)
'love as it happens' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'as it happens' becomes 'live' (as in live broadcasting).
'o'+'live'='OLIVE'
(Other definitions for olive that I've seen before include "A Med. fruit-tree" , "Its branch is a peace emblem" , "Oil producer" , "Stoned fruit" , "Mediterranean tree-fruit, nice in cocktail" .)