You guys have to train with him. She has to live with him. Sounds like sensei has a problem. Talk to her some more. Talk to him. Put it flat out that husband is killing her dojo by holding everybody, himself, her, other students, back. Find out if he's killing more than that. If she cannot get a handle on this problem, hand sensei a card for a marriage counselor and go train elsewhere.
How does rank manifest itself in your dojo? This guy may be holding your ranks hostage, but he really cannot be holding your aikido hostage. Anything stopping you from just being a whole lot better than he is and just doing your best aikido? What happens when you go to a seminar (preferably in your dojo's association, if you have one) and other folk see that you are being sandbagged?
I've been training in Aikido for nearly 8 years. I've been a 1st kyu for nearly 3 years now. I have an excess of over 1200 training days. I only need 300 days to qualify for shodan testing. I've been polite and quiet about testing for a very long time...because it shouldn't really matter. But, I've had a talk with my sensei and the idea of testing popped up and it came out the reason I, and a few other students, haven't been put up to test for black belt yet is because the sensei's spouse is still a shodan. Apparently this spouse has had a total fit about the sensei raising who they consider their juniors rank up to their rank.
A few years ago I tried to help their spouse train for their nidan test. They were lazy, made excuses for not training, wasted our time by not showing up when they said they would, they were verbally abusive when they got tired(cursed us out, blamed uke etc.)...they frankly were not taking to the training experience well. In all honesty this might had been the first time they had trained since taking their shodan test, so they were admittedly out of shape. (Another issue we students have, this person never trains but teaches the lion share of the classes...he's become a locker room joke actually.)
But apparently we all have been waiting so long to test because this supposed locker room joke isn't taking to losing his "place" in the dojo well. Rank shouldn't matter that much in my opinion, not that you keep the juniors from promoting because you lost pace. IMHO.
After three failed attempts to get this person ready for nidan, sensei is saying they are going to try to just get them promoted through recommendation. This person is in their 30's and doesn't have any physical issues other than letting themselves go a bit. I was told that I and my other long suffering 1st kyu would be put up to take my test when the recommendation went through...am I wrong to find this ridiculous? Me and my class mates have spent a lot of time, money and energy in this art. We have sustained injuries and some of us have had surgeries to cope with training accidents. We have busted ourselves and are now frustrated that we had to wait in line behind the laziest Aikidoka, some one who has been honest about having no love for the art who has admitted to just being in it to appease their spouse....some one who's been verbally abusive, arrogant, and over-all have ego trips at junior's expenses. We have to wait behind this guy!
There are no other Aikido dojo anywhere near us. If I didn't love Aikido I would leave the school, but there is no where else to train. Some of my fellow students have left because what they have considered double standards in the rules between he average student and sensei's spouse. Sensei doesn't seem to get why we are upset...we've talked to them about this issue already...and been dismissed. They have been clear in that they would choose their spouse over the school any day of the week...and I respect that, I guess.