That Cockney fellow allowing a little kiss, it's said, being virtuous? (10)
I believe the answer is:
impeccable
'virtuous?' is the definition.
('impeccable' can be similar in meaning to 'virtuous')
'that cockney fellow allowing a little kiss it's said' is the wordplay.
'that cockney fellow' becomes 'im' (Cockney pronunciation of 'him' - ie 'that fellow').
'allowing a little kiss' becomes 'peckable' (a peck is a little kiss).
'it's said' indicates a 'sounds like' (homophone) clue.
'peckable' is a homophone of 'peccable'.
'im'+'peccable'='IMPECCABLE'
'being' is the link.
(Other definitions for impeccable that I've seen before include "In accordance with the highest standards" , "Perfect - pure" , "Without fault" , "Immaculate" , "Faultless" .)