Consumed by pretty girl, Romeo’s boring crush (10)
I believe the answer is:
dishearten
'crush' is the definition.
'consumed by pretty girl romeo's boring' is the wordplay.
'consumed' becomes 'eaten' (similar in meaning).
'by' says to put letters next to each other.
'pretty girl' becomes 'dish' (I've seen this in other clues).
'romeo' becomes 'R' (phonetic alphabet: alpha, bravo, charlie etc.).
'boring' indicates putting letters inside (some letters must 'bore' a hole into other letters).
'eaten' put after 'dish' is 'disheaten'.
'disheaten' going around 'r' is 'DISHEARTEN'.
(Other definitions for dishearten that I've seen before include "Cause (someone) to lose confidence" , "dismay?" , "Take away bottle" , "cast down" , "Take hope from" .)