Why is watching pornography considered a major sin, while the preludes to fornication and sodomy are considered minor sins?

What we have issued a fatwa on is that watching pornographic films is a major sin, based on the saying of some scholars like Al-Haytami, that looking with lust, coupled with the fear of temptation (fitnah), is among the major sins. Looking, like other preludes to fornication, is originally a minor sin, but it becomes a major sin if it is accompanied by the fear of temptation.

Persistence in a minor sin makes it a major sin, as reported from Ibn Abbas, and scholars have consistently affirmed this.

Moreover, watching pornographic films may involve approving major prohibitions such as fornication and sodomy, and watching them is forbidden because it implies approval of them or assistance in them.

The danger of watching pornographic films to a servant's religion is indisputable. Disdaining a sin, belittling it, and not caring about it are among the causes of its sinfulness being magnified, for a minor sin may become a major one due to its being underestimated.