Master and I have experimented with anal play in the past. It was easier when we lived on the same campus, since we saw each other all the time and could work on it regularly. But then he graduated, and both of us bounced around the country (or the world, in his case) for a while, which isn't conducive to a regimen of any kind - especially a sexual one.
But now we've both settled down, at least for the medium-term, and so it's time to start once again. It's a little bit trickier since we're still in separate cities (albeit only 3 hours apart), but it was an obstacle easily overcome with TECHNOLOGY! I.e. silicone.
I found an awesome feminist sex shop in town and went to them for guidance. It was there I learned that anal training isn't about "stretching" anything - it's not even about getting used to something of that size up your butt. Instead, the goal is simply to become more aware of your muscles and to learn how to consciously relax them. I was glad to learn this, since the Master's-penis-sized toys they had available were a lot scarier (and pricier) than the smaller ones. I ended up purchasing one that's somewhat larger than an average man's middle finger, and in a very pleasant purple that matches the very first dildo I ever bought.
I wasn't expecting to accommodate the entire toy on my first try, but I did it with much greater ease than I ever managed when Master played with my ass. I think it's a combination of being more relaxed on my own - no performance anxiety! - and I was already somewhat used to the sensations. When I was with Master this past weekend, however, I started tensing up again, and it wasn't as easy. I'm also not able to handle any in-and-out motion yet. But I'll keep working on it!
Anal wouldn't be nearly as pleasurable if I weren't a masochist, I think. That isn't to say it hurts - I'm so paranoid about damaging something sensitive and important that the slightest hint of pain signals game over for me. However, it definitely isn't pleasurable in the same way that vaginal sex is. It's intense. I kind of want to compare it to a deep-tissue massage. And as a masochist I think I tend to interpret more kinds of stimulation as "pleasurable" than the average Jane, and I'm more open to incorporating them in sexual contexts.
Nevertheless, I'm glad that Master doesn't fixate on anal as some sort of sexual "holy grail" in the way that some guys seem to. He describes it as "Dominant icing on the cake of sex," which I think is a great way of looking at it. It's a lovely treat, but it's not the be-all-end-all, which means he doesn't get frustrated when I can't take him in my ass - something that happens quite often, since I still need to work on getting over that performance anxiety.
He mentioned he might get me a butt plug with a kitty tail on it. That would be awesome. :3