Seizing the opportunity for imposing on one’s good nature (6,9,2)

'seizing' is the definition.
The answer and definition can be both to do with ownership as well as being present participle verbs.
Maybe there's an association between them I don't understand?

'the opportunity for imposing on one's good nature' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'opportunity' could be 'in' (in can mean an opportunity or way into something) and 'in' is found in the answer.
'good' could be 'g' (abbreviation) and 'g' is found within the answer.
'one' could be 'an' (an apple is one apple) and 'an' is found in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?