I once dated someone who also had DID. it turned into a very unstable and explosive situation... simple version our problems ended up feeding each others triggers, which resulted in some very unsafe things happening..

longer version...

Dissociation is a very normal reaction to triggers (stress, anxiety, fears, feelings, ....) that the person can not handle feeling/doing at that moment.

people with DID have at least two or more of these special type alters that take control many times when the person is triggered.

I would start feeling something...anxiety, or depression, or stressed out, ...I have many different triggers including what most people would consider to be completely harmless/non triggering.

the one I was with would notice I was feeling triggered and go into a heightened state mind (some people call this hyper arousal or hyper vigilant.) so that she could understand my feelings of being triggered and help me. her internal system would perceive this state of mind as there must be some danger or something going on. the result she would start switching into her alters.

sometimes it was the other way around where she was upset about something and my internal system would perceive my girls problem as mine and take over trying to fix the problem for me.

(some places call this co dependency)

the longer we were together the more plus the more similarities we shared the more ended up feeding each others problems..it got to the point where neither one of us could function on our own..

not to mention we didnt know every one of our alters with in our own internal system of alters and what triggered them/what triggered the dissociating...then on top of that trying to understand each others internal system, what triggered them and what triggered the dissociating..

one of my alters was triggered by flashlights/small lights, but yet another one of my alters felt safer with flashlights/small lights. she also had some fears/anxiety...hers was the dark.... imagine the turmoil when the electricity went out during a winter storm. there I was cowered in my bed under blankets turning a small flashlight on and off while this girlfriend of mine was crying and screaming in another room where an alter took her, because it was dark. thats how the neighbors found us when they came to check to see if everything was alright. both of us ended up in the hospital mental ward. thats when we came to understand just how dangerous it can be for two people with DID to date/live together.

years later I discovered that situation could have been a heck of a lot worse because we both had suicidal alters, we both had alters that enjoyed the darker side of sex, we both had alters that could have killed each other trying to protect ourselves with knives. neither one of us knew for years those alters existed inside of us.

we are both still friends but we never again took our friendship to the intimate sides after that hospitalization.

Im not saying what you and this other DID person has will be doomed/wont work. just showing you the possible danger.

my suggestion if this relationship is something you want to build on, go very slowly and may I also suggest that the two of you keep your treatment providers in the loop so that if some unexpected alters take over you and this other person you are dating are ok together. having similarities with DID can be a good thing but its also a bad thing too because what causes you problems will also cause the one you love the same problems (co dependency issues)