Is this REALLY infallible doctrine of the Church?? [Everyone not married in a church is in grave mortal sin.]
Not that it will satisfy, but the short answer is “No, unless..”
One would actually have to look deeper to know more. Perhaps read the thread or other matter to understand the Church’s position on marriage.
Well, that's going to be the only options since no Catholic on this board will commit to answering straight up questions about their faith.