The question is problematic on several levels. First, it is overly familiar and illogical. Its very construction assumes that I in fact do plan on cutting it, which you have no way of knowing. Second, it evokes gender expectations that I don't subscribe to (and wish that you didn't). Third, it undermines a parenting choice I am actively making every day. And, finally, like so many questions we parents field, it imposes on the fact the answer may be far more intimate and emotional than I care to discuss with acquaintances and passersby.
Instead of dignifying the question with a response (or completely dissolving into a rant), I thought I'd focus on some of the practical reasons why having a little boy with long hair is awesome.