You do the math. Think if you are using your time wisely.
For those using the internet and computers to accomplish their work is an everyday hard battle. If your job doesn't involved researching the internet, or require you to chat with people or managing social media tools you will be unproductive and it will affect your job and relationships.
Show this to your boss so he/she will understand why do you need to bring home your work or do it over-time.
Good luck!