Teenage crush (5,4)
I believe the answer is:
puppy love
'teenage crush' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for puppy love that I've seen before include "Young romance" , "Adolescent amour" , "Young infatuation" , "Adolescents' strong feeling" , "Adolescent infatuation" .)