Bet you all need kissing for starters, close to mistletoe? Ecstasy! (6)
I believe the answer is:
yankee
'bet' is the definition.
(I've seen this before)
'you all need kissing for starters close to mistletoe? ecstasy' is the wordplay.
'for starters' suggests taking the first letters.
'close to' indicates one should take the final letters (the close/ending of).
'ecstasy' becomes 'e' (informal term for the drug).
The initial letters of 'you all need kissing' is 'yank'.
The last letter of 'mistletoe' is 'e'.
'yank'+'e'+'e'='YANKEE'
(Other definitions for yankee that I've seen before include "Informal American, a doodle dandy" , "American - bet" , "Y in radio alphabet" , "Northern soldier in the US Civil War" , "Informal name of citizen of northern states of USA - a doodle dandy" .)