But I think they forgot Matthew 18 where Jesus explicitly gives intructions on how to deal with things like this. It's a moderate, approach that escalates the pressure. In the end if your husband refuses to end the affair, he gets excommunicated.
It's nasty business, but Jesus did give the keys of the Kingdom to the church. Kind of a power-of-attorney. What we bind and loose on earth is bound and loosed in heaven.
The goal is always to restore the person. Sometimes the gravity of the threat of excommuincation is serious enough to get a person to stop. These days they just go to another church.
Too bad.
Sometimes I wonder if the dark ages were all that dark. We can learn a little from them.
Your husband can use the church going medieval on his a$$.