How many grams is your BP? Ive seen 75 g BPs take a small mouse. I can't say that I am the absolute authority on the subject, but I would think that it would be more stressful on your snake to eat 3 pinks then one small mouse, and in my experience, a small mouse is about the same size as a rat pup. If you are worried about it biting back, stun it, thump it or offer FT.