To do with some of us socialising (4)
I believe the answer is:
fuss
'to do' is the definition.
(thesaurus)
'some of us socialising' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'FUSS' can be found hidden inside 'of us socialising'.
'with' is the link.
(Other definitions for fuss that I've seen before include "Worry unnecessarily or excessively" , "(Show) excessive concern" , "Protest, complaint" , "Commotion - worry" , "Agitation, maybe about nothing" .)