TLDR: Current LTR has recently displayed some red-flag behaviour, which led me to talk to her ex BF, who told me that LTR had deliberately cheated on him to get to me, and when he dumped her, threatened to file a rape charge against him and fabricate evidence, as a desperate measure to attempt to stay in the relationship (even though she had apparently already branch-swung.)

MAIN:

Actually, that's really about it. I haven't had any serious accusations thrown at me at all, and LTR has no idea I know what she did before we got together. As you might expect, I had no suspicion of behaviour to this effect until recently (surprise surprise). I've been on TRP for a while, but unfortunately failed to notice any issues until I actually got into the relationship.

How do I safeguard myself as well as possible against a possible charge such as this if I were to plan out an exit from the LTR in the future?