The only thing that even suggests sexualising the image is the presence of the penis. Take that away and there is nothing there suggesting sex at all. And the penis comes out of the girl's mouth. For whatever reason, she has a penis coming out of her mouth - and it appears to be that, specifically, that causes it to be a thing that sexualises, despite its presence being incongruous - a penis for a tongue. One girl's arms are the other girls legs, and she has a penis coming out of her mouth, as if the girl on top is fucking the back of the other girl's head with her penis, which is somehow going straight through her head.
But substituting a girl's tongue for a penis in that way is not paedo-pornography. TBH that people would think it is says more about them than the artists or the art work.
As for this idea that we need to protect the children, well take a wander around any gallery with old masters in it. Take a thumb through a book on Goya. You will see all kinds of unpleasant things. Art isn't just about sunflowers.
Hell, take a wander around a church and look at all the images of a man nailed up to a cross and left to die.