I'm not a doctor or therapist but I wonder if he may have been triggered by anything here recently? Has anything changed like new people that you two have been around lately? Or has there been any children around that may have triggered him? I know these are difficult questions to answer but just think about things lately that could have been different than before.
Another thing that may be going on is that he may feel safe now! When a survivor grows up and is now in a safer environment, the safety could make them feel more at ease and that sometimes "helps" with the memories and pictures showing up. Has he become more agitated lately too? That could be because of the pictures in his head. For me, the pictures were so sickening that it made me very ill. Let me know if you can remember anything else and maybe that could help you to understand. I know it must be scary but I assure you that with time and treatment he will become stronger and healthier.
Please keep me informed and I will try my best to get you through this. Is he in treatment yet? Has he seen a psychotherapist or psychiatrist? Is he just now learning more about all of the alters or has he known about them?
Stay safe! And keep writing, it helps even the supporters of survivors!!!
Contact me anytime you want to! Candy

Dear Vanessa
wow your letter is so much like what i am going through. my friend in the US has alters that i have also fallen in love with. it does hurt because he came and went and now is going again. they have all spent holidays here and we have had fun times going around london. i got to know them real well and they became good friends. many people can not understand hoe yoiu can fall in love with someone you only hear and never see but you can. because its built on trust, i hope your one comes back as i hope my one will. only thing is i live in the UK and they live in the US so we talk on the phone a lot, good luck with yours