I was a fundie when I married my wife. Fundies were rude to Mormons when we tried to find a church for me to attend, so I started going to LDS services. I made friends, got callings and gave talks. I was an inactive member. I was also open about my doubt with her. This wasn't the whole time. There were places we lived where neither if us went, or we just went to sacrament, or she went alone etc. We had times when religion was a wedge, and we had to work through it.
12 years later, I joined, and we even got sealed. I started questioning, seriously after the temple.
7 or 8 years later, she was still TBM, and she knew I was doubting. I did my clerk calling, and skipped everything else. I was mentally out, she knew it, and it hurt her. But we still loved each other. The branch we were in, got an abusive president. She got so fed up, depressed and anxious that we left to another branch. (The old BP told us we needed the PROPHET to give permission for us to switch, and the new one told us he was insane to say that.)
After a few months, trying to make friends, trying to get into it all at the new branch, she told me she was too tired and didn't want to put in all that work again. We stopped attending, I was realizing I didn't believe in God anymore, she was just tired of the Church.
Our kids had their own journey out at that time. A couple had already checked out mentally by then.
That's been 10 years ago, roughly. In the last few years she discovered exmo Twitter and YouTube, learned about the CES letter etc.
We are both out together now, and so are our kids, now grown.
Our marriage has been happy. Even now, struggling with grief unrelated to TSCC, we are stronger together. Last year was our 30 year anniversary.
Every occasion where my religion or her religion told us we shouldn't be together, we chose love. I think that is why it's working.