My spouse looks at porn once in a while, but not very often. Is that ok? How much is too much?

Any porn use is too much. Porn always leads to exploration down dangerous avenues. Even if a person were able to avoid becoming addicted, watching porn leaves marriage behind and replaces it with lusting after another in his heart and mind.

Anyone who looks at a woman lustfully has already committed adultery in his heart.

(Matthew 5:28)