A person can be an unloving spouse without being sexual unfaithful.
I would say this is true.
But God wants us to do all things in His love. Or else, we are not being faithful to Him or our spouse. Because we are having affairs with what is not love, even if these affair things are nonsexual > we are not being faithful to how Jesus wants us to love.
"Do all things without complaining and disputing" > in Philippians 2:13-16 < our Groom Jesus wants us to relate only in His love; so we are cheating on Jesus by having affairs with complaining and arguing!!
So, I would say you are technically correct to say that it is possible to be unloving even though you are not cheating sexually, but - - - faithfulness in Jesus is more about spiritual relating, including always being ready to forgive. Also >
"Husbands, love your wives and do not be bitter toward them." (Colossians 3:19)
This is included in being faithful to our Groom Jesus, including by not having any relationship with bitterness.
I think not loving your wife is probably the bigger one to the woman. I think both are equal sins to God.
I think it is right to consider that being unloving can be what can bring on being sexually unfaithful . . . as
It sounds like the first sin would necessarily "require" the second one as well.
And other sinning can help to make a man more and more weak so he fails to love and then can break down into adultery. If this is so, even the lesser sins and ignorant ones can be helping to bring him eventually to adultery or to being worse about not loving her.
So, while I do not believe that every sin is equally wrong, every one can contribute to someone getting more and more away from loving the way we can in Jesus. And the battle can be in us, mainly against the emotional things and negative thinking which can take us down, first, and then we can get into more outward things.
"Let all bitterness, wrath, anger, clamor, and evil speaking be put away from you, with all malice. And be kind to one another, tenderhearted, forgiving one another, even as God in Christ forgave you." (Ephesians 4:31-32)
So, we need to keep our forgiving up-to-date, being generous and gentle to forgive. And I think of how Jesus prayed for Peter even before Peter denied Jesus three times; so I see I need to pray for people even before they mess up, and be ready for them to get blessed back > like Jesus did with Peter > Luke 22:31-32.