I work with my girlfriend at a fortune 500 company. I figured out her password to her work computer (outlook email), and found out she chatting with another coworker in a really flirty way. I want to confront the both of them in an email. My question is... would that be grounds to terminate me if... she went to HR and told I was looking in her email unauthorized?

Thanks in advance!

Yes, it most likely is grounds for termination. You essentially "hacked" her password and I am sure that is against the rules and regs of the company. It is an invasion of privacy issue as well.

Many Fortune 500 companies have a policy against dating co workers also, does your company? Do they know you are a couple?

Not only is it probably a violation of corporate policy but it's a violation of federal law.