Alluring old lover twitching, concealing love (6)
I believe the answer is:
exotic
'alluring' is the definition.
(thesaurus)
'old lover twitching concealing love' is the wordplay.
'old lover' becomes 'ex' (I've seen this in other clues).
'twitching' becomes 'tic' (tic is a kind of twitching).
'concealing' indicates putting letters inside.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'ex'+'tic'='extic'
'extic' placed around 'o' is 'EXOTIC'.
(Other definitions for exotic that I've seen before include "Unusual and showy" , "Colourful or unusual, perhaps from abroad" , "Strikingly strange or unusual" , "Weird; alien" , "From a foreign place" .)