Not only atheist who watch porn benefits from it but also everyone who watch even if it’s a religious person. There are many reason to support this thought.
I believe a consenting adult has the right to choose who they sleep with, what they watch—whether it is a rated R movie or a porno—and what they listen to. Moreover, I believe adults who wish to watch other consenting adults engage in sexually explicit behavior may do so, as long as there is the clear understanding that all parties involved are of age and have freely given their consent. But I have sociopolitical and scientific reasons why pornography should be permitted also.
The Porn Report, published by Melbourne University Press, collected interesting statistics on porn. The researchers found that there is no difference between right wing or left wing constituents when it comes to viewing porn, and more surprising still, they found that over 60% of pornography viewers happened to be religious (interestingly enough only 32% of atheists view porn regularly).