A nose plant is somewhat inevitable if you're going to eat from the back. I'm more of an eat from the front man tho since you don't have to stretch the tongue so much to reach the clit, which can lead to early fatigue and an uncomfortable wound on the underside of the tongue caused by your lower incisors. I have never, however, effected an anal penetration with the nose. My $.02 and JMHO on this hotly debated topic.