Indulge in Prince and Queen (6)
I believe the answer is:
pander
'indulge' is the definition.
(I've seen this before)
'prince and queen' is the wordplay.
'prince' becomes 'p' (abbreviation).
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'p'+'and'+'er'='PANDER'
'in' is the link.
(Other definitions for pander that I've seen before include "Gratify weakness like a pimp" , "Cater rto debased tastes" , "Indulge or cater to" , "Cater for vice or low tastes" , "Give gratification (to)" .)