Please have a look at the following:
"I think parents with teenagers should be open-minded on almost everything."
"I agree, but never when__________to drugs."
b.does it come (given as correct)
I know we can invert after never, but here the inverted option doesn't sound good to me....
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.
Never (should it happen) when it come to drugs.
That's where the inversion would be.