It sure doesn't make things easier. (With some exceptions.)
My wife is in the midst of therapy now. Intimacy is certainly an issue...
Also the extra time making sure everyone is satisfied (painting time, reading time, puzzle time, etc.) in addition to 4 outside kids and work, and side job can be taxing. It's a lot of work maintaining a relationship with 17 (including Sunflower).
When Sunflower is willing to accept help from the insiders, things can go pretty smoothly. Often though, she won't and will "lock up"/panic over relatively basic issues like a flat tire.
I've spent a lot of time reading books and playing games with littles in an adult body. It takes an open mind and a lot of patience. I don't have a lot of people I can share it with either. Coworkers would look at me funny if I told them, "So, last night my wife's alters got in an argument. One was out, but the other got control of the hands and used the hands to hit the other one in the face with a pillow!"

*True story.*
I sit in the bathroom almost every time she takes a shower as it helps to comfort Dinah.
Several will send me texts, but delete them on her phone, so I show her on my phone what happened. Speaking of texts, there is innner turmoil in the system with one who is resistant to therapy. Got a text asking for help with a puzzle, then another saying nevermind. Shortly thereafter "Please?" followed by, "Nope, just figured it out." When I went over to figure out what was going on, Emma was upset I hadn't come sooner. Just an average day of confusion...
There are good thing for sure as well. Meg will give me suggestions of what SF wants for gifts. When I get time with LR, the blah intimacy turns to awesome. Lou is a lot of fun to be around. AJ likes to do outdoorsy stuff with me. And overall my wife is more confident and emotionally well rounded in the past two years since we learned about DID.