Old man / lover won’t get over friend (3)
I believe the answer is:
pal
'friend' is the definition.
(pal is a kind of friend)
'old man lover' is the wordplay.
'old man' becomes 'pa' (both can mean father).
'lover' becomes 'l' (this could be a standard abbreviation which I don't know about).
'pa'+'l'='PAL'
'won't get over' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for pal that I've seen before include "Mate, buddy" , "Mate, informal friend" , "Friend (colloq.)" , "Brother" , "Buddy, chum" .)