How to get fucked in the Ass without feeling pain

It takes patience and practice. Remember you're trying to get something to go the wrong way up a oneway street. You have to practice with something smaller in girth than your average penis, make sure it's well lubed and gently insert it very slowly while at the same time learning to relax your sphincter muscle. Best bet is to go to a sex shop and buy a smallish dildo which has the same consistency as a normal penis - not made of hard plastic and use that. The clerk at the shop will guide you to the right product. Practice, practice, practice!! Slow and gentle and one day you'll be able to do it without it being so painful.
Good luck :)
Let me know how you fare with this.

I agree with most of what's been said already, with exception to marquella.wells. I taught myself anal with objects (carrot, cucumber, fingers, dildos, etc) & with a dildo or penis the size of mine I can take it in painlessly. I have been privileged to teach anal to a couple of women as well, who both loved anal from then on & one actually preferred it. I start with my pinkie finger & graduate up by size, slowly & making sure that there's no discomfort. I work all the way up to my thumb, then work on inserting two fingers & so on until it's relaxed enough to take my dick. One of the ladies could even have an orgasm doing anal. Oh yes, plenty of lube!

On your own, use a well-lubed dildo to stretch each day. When you do have him enter your anus, make sure he is well lubed and inserts just the head to start. After two or three entrances / days, there will be no pain - just pleasure.