Jerk stabbing Caesar's associate, maybe with passion (12)

'with passion' is the definition.
(done with romance or passion)

'jerk stabbing caesar's associate' is the wordplay.
'jerk' becomes 'tic' (jerking movement by the body).
'stabbing' is an insertion indicator (some letters stab themselves into others).
'caesar' becomes 'roman' (Julius Caesar was a Roman figure).
'associate' becomes 'ally' (ally is a kind of associate).
'roman'+'ally'='romanally'
'tic' placed into 'romanally' is 'ROMANTICALLY'.

'maybe' is the link.