I lubed up and shoved it in. Since he's done a lot of sport, I knew he was used to some pain, so I didn't try to go too slowly at first. I just gently got through the two rings and then went to town. Both doggie and missionary, he didn't put up too much of a fuss, but when I started ramming him from behind, he starting gritting his teeth and expressing his displeasure. I kept going anyway of course, just glad that I had him pinned down enough to keep him from running.