Going on and on about kiss being superficial (8)
I believe the answer is:
external
'superficial' is the definition.
(I've seen this before)
'going on and on about kiss' is the wordplay.
'going on and on' becomes 'eternal' (I can't explain this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'kiss' becomes 'x'.
'eternal' enclosing 'x' is 'EXTERNAL'.
'being' is the link.
Can you help me to learn more?
(Other definitions for external that I've seen before include "Outward" , "Surface" , "Relating to the outside" , "Outer" , "Lying outside" .)