The prostate gland is in the middle of the pelvis and produces part of the fluid (called seminal fluid) that comes out when a man ejaculates. You can't touch the prostate directly, but it is possible to stimulate it indirectly both through anal stimulation and external stimulation of the perineum. Some men have enlarged prostates that can cause pain or discomfort when stimulated (this can be the result of a medical condition or of medication one is taking).
But for many men the prostate is a wonderful sex organ that provides deep sexual pleasure. It's not particularly accurate, but some people have started calling the prostate the male g-spot. Others have, unfortunately, started referring to it as the P-spot.
Wash up, and relax.
Many of us have issues with cleanliness when it comes to exploring anal play. Having a warm bath or hot show may help alleviate anxiety about this. It also helps to relax you, which is an important state to be in for any sex play. Finally, the bath or shower can be a great place to explore. Because feces only travel through the rectum on the way out of the body, you won’t find very much there. If you are concerned about having a bowel movement during prostate stimulation, make sure you go to the bathroom before you begin.
Trim your nails and smooth out the rough edges.
The lining of the anus is very sensitive and can be torn easily. If you're playing with sex toys, make sure they are safe for anal penetration. Consider using latex or nitrile gloves. They are a good way to deal with hang nails and small cuts on your hands, plus if you have any concerns about cleanliness they provide a barrier between you and all your bodily fluids.
Turn yourself on.
Because the prostate swells when aroused, it’s easier to locate when you’re hot and bothered so watch an adult movie, masturbate, fantasize...whatever gets you in the mood. Unless the scientific approach is a turn on for you, trying to find the prostate in a dispassionate way is neither the best nor more enjoyable approach.
Find a comfortable position.
If you are exploring on your own find a sex position you are most comfortable in where you have access to your bum. Try lying on your side, or squatting. Sitting in a comfy chair might work, or lie on your back with your legs in the air. You need a position you’ll be comfortable in for a while. Using pillows is always a good way to get comfortable.
Start on the outside, massage your anus and perineum.
You never want to rush the penetration part of anal play. Start with an external massage. The perineum is located between the scrotum and the anus. Many people find that massaging the perineum is relaxing and pleasurable. You probably won't be able to feel the prostate with your fingers while massaging the perineum, but you are actually stimulating it indirectly. Massage the anus using a rhythmic, circular motion. You can gently push on the anus as if you're ringing a doorbell, without forcing your finger inside. This will help relax the anal sphincter.
Go on in.
When you are ready to insert a finger in the anus, try to tune into your breath. You can use conscious breathing techniques to deepen your awareness of physical responses. Make sure you have lots of lubricant on hand, literally and figuratively. The best way to insert a finger in the anus is to start with the pad of your finger first (not the tip). Gently put the pad of one finger up to the opening of the anus and leave it there while you breath. When you are exhaling, push out as if you’re trying to go to the bathroom and you should feel your sphincter muscles relax a bit and your finger should be able to slid in. Once inside, rest a moment while you get used to the sensation of having something in your anus.
Find the prostate.
You should be able to feel the prostate about two inches in and toward your belly. It is often a walnut-shaped bump. Some men will know when they are touching it, others won’t notice much at all. It can be easier to have someone else find it for you (if you happen to have someone handy!)
Experiment with different kinds of touch.
Once you’ve found the prostate you can experiment with what feels good. Some people like the feeling of consistent pressure on the prostate, others prefer vibration, or an on-off kind of pressure. You can also experiment by squeezing your PC muscle and see how that changes the feeling.
Using sex toys.
Anal sex toys can be a great way to explore prostate stimulation. Toys that have a slight curve are often designed for prostate stimulation. Some toys will vibrate, which is a completely different kind of sensation that some guys like and others don’t. If you’re going to try a vibrator, be sure to get one with variable speed, so you can start slow if you want to.
Butt plugs are anal toys designed to be inserted in the anus and stay in place. Some guys will put in a butt plug and then have other kinds of sex play (either masturbation or play with partners). Many say that having a butt plug in (which provides a mild but constant prostate stimulation) really changes the way that their orgasms feel.