rikter8: AND it feels good, if done properly.
What you want to do, for a first time anal newbie is use LOTS of lube and LOTS of foreplay in the anal area.
It may help to work the fingers quite a bit in the anal cavity to "Loosen it up"
Otherwise it will be really painful.
Also, Very important....you want to make sure that the bowels are EMPTY.....otherwise it gets really messy and you can cause compounding of the bowel which is also painful. Enema's are your friend.
Squeaky clean is the best way to be for anal sex.
Not only is it fun, theres no suprises.
I've helped a lot of younger guys for their first time, and everyone appreciates someone taking their time to show them the ropes - especially when it comes to anal.
Take your time, use a good clean lube, Condoms and have fun!