I used to want it really bad but the ex was against it, i had a friend (girl) that was very open about liking it, so on a drunk night while we where both single I jokingly told her to "teach me how to fuck an ass". Well I learned a lot, preparation is key and most people dont even think about it. Cleaning and proper lube go a long way to make it enjoyable to the girl. Still the only girl I did in the ass.