One of the great things about porn is that it simplifies human sexuality. The female is completely objectified, but so too is the male. The male actor becomes nothing but a penis - the 'stud', so to speak. His cock becomes the most important part of him. And porn is about the pleasuring of the cock. In scenes with two guys and one girl, there are three dicks being exposed and pleasured - those of the two actors and that of the masturbating viewer (assuming there is just one viewer). The actress can do anything she wants with their cocks - stroke them slowly or rapidly, lick them, suck them, tikcle them, allow them to touch each other. The point is it doesn't matter if the two cocks touch, for they are but putty in the hands of the sweet nymph in whose hands pleasure resides.