You need a calorie deficit to use topical. What could possibly end up happening is the fat being "redistributed" throughout the body. This is described over at Avants site in detail, but basically your answer is: yes, reduce cals. I'm too lazy to give you all the details now, but look over at Avant or BB.com for all the specifics from Dante. If you're bulking, maybe consider HIIT cardio I guess.