Dan's involved with girl and both are in love (7)
I believe the answer is:
darling
'love' is the definition.
(both are terms of endearment)
'dan's involved with girl' is the wordplay.
'involved with' indicates an anagram (involved can mean confusing or complex).
'dan' mixed up with 'girl' gives 'DARLING'.
'and both are in' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for darling that I've seen before include "lover" , "Pet" , "Victorian heroine" , "Grace -, nineteenth century wreck heroine of lighthouse" , "Film with Julie Christie and Dirk Bogarde - sweetheart" .)