Perhaps Yoko doesn't fancy being alone (2,4,3)
I believe the answer is:
on ones tod
'alone' is the definition.
(I've seen this before)
'perhaps yoko doesn't fancy' is the wordplay.
'perhaps yoko' becomes 'Ono' (musician Yoko Ono).
'fancy' indicates anagramming the letters.
'doesnt' anagrammed gives 'nestod'.
'ono'+'nestod'='ON ONES TOD'
'being' is the link.
(Other definitions for on ones tod that I've seen before include "solo" , "Alone" , "reverse of 9 [AIDED] ?" .)