Levier,
First off, NONE of us know the type of personality you have. We all can make assumptions based on our OWN personality or sense of humor, but as you can see you will continue to get mixed advice here.
first, no matter what anyone here says, you arent a douchebag. it WAS a joke, whether it was a good or bad joke is really irrelevant. your INTENTIONS is what should matter.
you have been dating this women for 3 months. which i would ASSUME that she knows what type of personality you have. Even if this type of comment is not common for you, it was explained to her that it was a joke. does this joke, bad or good, determine the outcome of you two spending time together??? i say absolutely not.
Had she thought you were serious, and was offended, then i can understand her breaking off plans, but to me, IMO, this seems to wreak of unnecessary drama.
Whats even scarier for me Levier, is the thought you have put into this. The time and effort you have spent trying to rectify the situation seems overboard in itself. You arent concerned about her breaking same day plans via text message or even an apology, but you seem to be concerned about something you didnt mean.
The one thing i have learned ...is not to worry what ANYONE thinks of you. You cant expect to please everyone. Just be you. When it comes to relationships, if you have to apologize on a REGULAR basis, for things this trivial, believe me, it will be a short lived experience.
...by the way, I think the joke was horrible... "eat sausage".. com'n brother. If I was her I wouldve told you not to hang tomorrow simply because your joke lacked humor and creativity. you gotta bring it stronger than that