Giving, but quietly feeling bitter about it? (10)

'giving' is the definition.
(presenting is a kind of giving)

'quietly feeling bitter about it?' is the wordplay.
I cannot really see how this works, but
'quietly' could be 'p' (p for piano and quiet) and 'p' is located in the answer.
'about' could be 're' ('re' means regarding or about) and 're' is found within the answer.
'it?' could be 't' (abbreviation. e.g. in 'tis) and 't' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

'but' is the link.

Can you help me to learn more?