Its up to you. What are your goals? If you want to gain muscle, you can probably get away with eating a bit. If you want to lose fat, well, you are only hurting yourself every bit of candy you have.
The extra calories aren't always the biggest problem, but the insulin spikes, the saturated and trans fats, and the timing of the bad food are usually what gets you.
But remember, if you are sticking to a good diet and exercising regularly, eating some bad food every now and then is not a problem