I'm going to make my girlfriend's roommate cry
Why do you want to do that?
She can't stop interfering in my relationship with my girlfriend and is taking up time that I should be able to spend with my girlfriend.
You can want to spend more time with your girlfriend. But she gets a say in how much time you spend with her, don't take it out on others  if you're frustrated.
But it's so annoying!
Whether or not it's annoying doesn't mean you should go out of your way to make her cry.  Respect your girlfriend's relationship with her roommate and learn to deal with other people being active in your girlfriend's life!