I'm Bisexual. It takes time, patience, and remaining as relaxed as possible to open up for anal sex... (if you have never done any butt play with insertion) The guy you are with needs to be patient and not be in a rush to put it in. You will need to relax as much as possible (which means don't panic or be afraid) Try not to clench your butthole, because doing so will tighten you up and you want to be loose enough for penetration. Open up with something small in diameter, such as a finger or a small butt plug. A small "narrow diameter" vibrator could also help. (the vibrations help ease the discomfort) Being an anal virgin (first time) you will likely want to take things slow. This is an area that you do not want to rush because of the possibility of pain and injury. There are 2 sphincter rings of muscle in the anus. One is on the outside (butthole) the other one is right behind it. Both must be loosened for anal sex. If you insert a finger and it hurts, try to relax. Pushing as though you are trying to poo works for some people. Make sure you are cleaned out (enema) to avoid "accidents". Often, the most common feeling is that you need to take a dump. If you are cleaned out (enema) you will know that it is not that. The feeling is one of being full and the sensation to poo will pass. The stimulation to the Prostate is fantastic (at least for me) and I enjoy it. But the 1st time I had anal sex, it hurt a little. But not a lot. There was no blood. The person I was with was patient and made it clear to me that their interest was in me having a pleasurable experience. I was told that if for any reason I changed my mind and did not want to experience anal sex, just let it be known and it would be no problem. So make sure the guy you are with understands and accepts that you may change your mind and not to get upset if things don't go in that direction. Patience, understanding, and a selfless desire to satisfy you are the keys to this experience being something you might enjoy and want to repeat. It is not easy to relax if he is well endowed, but it is possible. Knowing that he can be trusted to take the necessary time (it varies from person to person) to open you up, goes a long way toward helping set a relaxed atmosphere. There should be no pressure on you to submit. The partner "must" be trusted. So whoever you decide to help you with this experience, be careful! Anal Sex can be very pleasurable or very painful. If you don't like something you have the right to say "No". I hope this helps.