Kiss in film, touching film, one going all the way (9)
I believe the answer is:
extremist
'one going all the way' is the definition.
(someone going to an extreme)
'kiss in film touching film' is the wordplay.
'kiss' becomes 'x' (X can represent a kiss).
'in' indicates putting letters inside.
'film touching' becomes 'etre' (I can't explain this - if you can you should believe this answer much more).
'film' becomes 'mist' (I've seen this in other clues).
'x' put inside 'etre' is 'extre'.
'extre'+'mist'='EXTREMIST'
(Other definitions for extremist that I've seen before include "One with views far from the mainstream" , "immoderate person" , "An ultra-radical" , "Fanatic, hardliner" , "His views are anything but neutral" .)