What could make my pants offensive to others? (9)
I believe the answer is:
halitosis
'what could make my pants offensive' is the definition.
I can't tell whether this definition defines the answer.
'to others?' is the wordplay.
I cannot quite see how this works, but
'to' is found in the answer.
This explanation may well be incorrect...
(Other definitions for halitosis that I've seen before include "offensive condition" , "Smelly breath" , "Bad breath, smells unpleasant" , "Foul breath problem" , "repulsive pants?" .)