What does the cryptic crossword clue "Jerk with relations taking drugs? I don't think so! (4,3,5,3)" mean?

The definition is "think so!". The wordplay uses a double definition. Double definition The answer is PULLTHEOTHERONE.

Jerk with relations taking drugs? I don't think so! (4,3,5,3)

Guardian Cryptic #27044 | 9 Across | 2016-11-17 flower