Girlfriend Stolen

You and your girlfriend Mia were a perfect couple. However, the last few days she's been acting a bit strange. Unbeknownst to you, your girlfriend's body has been possessed by someone else. Feel free to muck around with the Memory to add things like a cause or a way to undo the possession at your leisure. NSFW enabled by default. This is my first scenario! Comments, suggestions, and ideas welcome. The tone of the scenario can fluctuate wildly depending on which option you pick. Edit 1: Added Dirty Old Man option. Added some more tags. Edit 2: Added the Office Rival and Serial Killer options. Edit 3: Added the Alien option and its two sub-options. Edit 4: Added Mortal Enemy option. Nice suggestion : ) Edit 5: Suggestion is correct. This definitely needs a parasite option. Now added. Edit 6: Added an Animal option with Dog and Cat sub-options. Edit 7: Suggestions are correct. Added Demon, Angel and customizable Ghost options. Also, by popular demand, finally added a 'You' option. Sorry it took so long! Edit 8: Added Concerned In-Law, Jealous Ex (with both 'still loves you' and 'resents you' sub-options) and Elderly Nursing Home Patient options. Also switched rating to Unrated, just in case. Happy new year, everyone! Edit 9: No new content, just switched back to Mature to test if it passes. Will switch back if not.