Discord is unable to surpress his instincts and begins to go into rut. In preparation he makes himself a place to hide and wait it out so he doesn't hurt his wife. Assuming that Fluttershy would stay away proves to be a miscalculation.
"Any religion that allows or commands you to pass judgement on, convert by force, or kill another human being is not a religion that serves any interpretation of any God or Gods above." Unknown