Re: Here's one you probably haven't heard before.
In my opinion it sounds as if she genuinely needs some space. She has borderline personality and that can be difficult enough to deal with on its own, but combine that with suicidal thoughts and you have a recipe of a mental breakdown. I would not take it as her way of being able to sleep around without feeling guilty.
Hang on in there and give her the time she needs.
~ The journey of a thousand miles begins with a single step ~
* Nothing in the world has ever been accomplished without passion *