Is it reprehensible for a husband or wife to imagine having intercourse with someone other than their spouse, or is there a difference of opinion regarding the ruling on this matter?

Scholars have differed concerning the ruling on one spouse imagining the image of a foreign person during intercourse. Some have permitted it, some have deemed it reprehensible, and some have forbidden it, which is the opinion of the majority. This act is considered one of the devil's gateways for corrupting the relationship between spouses. Therefore, thoughts concerning these matters must be guarded, for neglecting thoughts and indulging them is the root of all corruption.