Trouble over one lad's love affairs (8)
I believe the answer is:
liaisons
'love affairs' is the definition.
'trouble over one lad's' is the wordplay.
'trouble' becomes 'ail' ('ail' can be a synonym of 'trouble').
'over' shows that the letters should be reversed in order.
'one' becomes 'i' (Roman numeral).
'lad's' becomes 'sons'.
'ail' written backwards gives 'lia'.
'lia'+'i'+'sons'='LIAISONS'
(Other definitions for liaisons that I've seen before include "Secret relationships, often illicit" , "Alison is embroiled in affairs" , "Affairs or mediations" , "Romance or mediations" , "Illicit love affairs" .)