A large sweetheart completely done with (3,4)

I believe the answer is:

all over

I'm a little stuck... Click here to teach me more about this clue!

'done with' is the definition.
(thesaurus)

'a large sweetheart' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'sweetheart' becomes 'lover' (sweetheart can mean a lover).
'a'+'l'+'lover'='ALL-OVER'

'completely' is the link.
I am not very happy about this link. It may be part of another bit of the clue.

Can you help me to learn more?

(Other definitions for all over that I've seen before include "typically" , "covering everything" , "Obsessed with" , "Finished" , "Everywhere (bar the shouting?)" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.