Throwaway for obvious. I want to find out if there's any way to protect myself legally from a possible false accusation of rape.

I had been meeting this girl to hang out for the past few months. Yesterday we hung out in the afternoon and evening- going to a festival, drinking at a bar, getting food, etc. It was a pretty good night, no red flags yet.

EDIT: She and I have hung out a few times as strictly friends, and nothing more. It wasn't until she asked me to watch a movie with her that I started noticing romantic advances from her.

Around 11pm, we decide to head back to my place and "watch a movie." Not soon after, we obviously start getting close and make out. We then take each others clothes off and start giving each other oral. I had a mad case of whiskey dick and couldn't get the sailor stiff to have legit sex, but she was clearly cool about it. We're joking around, having fun still. No problem.

We start to cuddle and watch the movie again, and she brings up how she really likes me. I mention to her that I enjoy her company, but that I'm also involved in an open relationship with a girl who I have been dating seriously for 7-8 years. She immediately gets up, and replies that she thought I didn't have a girlfriend. It was very clear that she wanted something more than a friendship or FWB, but I didn't want anything serious at the moment.

Upset, she gets up and starts going through all of my kitchen drawers. Puzzled, I asked what she was looking for. Initially with no response, she finally yells, "why the fuck don't you have any sharp knives?" This girl was about to cut herself in front of me. Nice. Thankfully, I convinced her to stop what she was doing. She left pretty quickly afterward.

Clearly this girl wasn't in the right state of mind. I am concerned that because the girl I chose isn't her, she could potentially do something even more irrational.

tl;dr: Girl comes over, we have consensual sex. She finds out im in an open relationship with girlfriend of 7-8, goes batshit crazy and tries to cut herself in front of me because I don't want to date her seriously. Now im paranoid she'll do something crazier.

I figured if there's any place on the internet that knows about legal situations like this, it's MensRights.

Any help?