Loss of space

My G/F read one of my e-mails today. The subject matter wasn't the most Christian. Which is a good thing since I am the farthest thing from a "good Christian".
But now the question is being posed: Do I stay or should I go?
The e-mail simply asked if I was going over to a friends house after work one night and made reference on to how this woman was given the green light to have a 3-some. Nowere in the e-mail did it state that I was involved, but somehow that's what my G/F concluded, and now I've been asked to promise not to go over there. I don't think I will make that promise. I shouldn't have to make that promise.
Should I?