DEAR DR. JENN,

Last time I gave my boyfriend oral sex, he asked me to put a finger into his butt. This totally freaked me out. Why does he want me to do that? Even if I were going to try, I'm not even sure how. Help? — Butt Why

DEAR BUTT WHY,

Let me be the first to tell you that anal stimulation for heterosexual men is the hottest new trend since herringbone. Your boyfriend is no dummy. Stimulating, massaging, or milking the prostate can result in orgasms that are 33 percent stronger than average. And as men of many sexual orientations know: The best way to get to that prostate is up the butt. That's just where it is.

What is the prostate?
The prostate is a small, walnut-sized gland located just beneath a man's bladder. It surrounds the urethra like a doughnut. When a man becomes aroused, it swells up with the fluid that makes up semen, sending pleasurable sensations throughout his loins as he nears orgasm. The "P-Spot," as some call it, can be located and stimulated by putting a well-lubricated finger two to three inches into a man's anus. This can result in what some men described as full body orgasms. Women can enjoy this, too, by the way. While women don't have a prostate, there is a high concentration of nerve endings in the area.

Protection Is Key
Most people know that anal intercourse is a high-risk activity when it comes to HIV. Manual play is a little more of a gray area. The mucus in the lining of the rectum of an HIV positive person contains the virus which can be transmitted. In addition, because the area is so fragile, it can tear easily which means that there could be blood which is a high risk fluid to play with. In order to play safely, latex gloves or a finger cot is recommded.

How to start anal stimulation? Slowly.
Let me share a few tips to make that finger situation more pleasant for both of you. Any kind of anal play is always best done after a shower. Some super considerate lovers even opt to give themselves an enema beforehand, but that is not necessary. If you are concerned about things getting messy, put a towel down where are you are planning to play. And speaking of being considerate: Make sure your fingernails are trimmed or filed. This is not a self-lubricating area, so you will need to use lubricant. I recommend a silicone based lube for this, since it lasts longer and cuts down on reapplication.

Once you are gloved and lubed up, you want to ease into the situation. A little touching before penetration is nice no matter who's giving or receiving (and where), and anal play is no different. It's a hyper-sensitive area and can bring men off-the-charts pleasure, but a slow start makes all the difference.

The nerves around the anus are the same branches that reach his penis and testicles. Having physically relaxed muscles is important for this to be a pleasurable experience. Learning to receive stimulation to a new part of the body can take some getting used to. This tends to be most successful when he is already turned on, at which point you may want to start by gently touching at and around the opening. When you do eventually put your lubricated finger in, go slowly! Make sure to be sensitive to any feedback that he is giving you. Getting familiar with an anatomy chart can help you to find the prostate even more easily. (The Pleasure Mechanics have a great instructional video.)

VIDEO: 5 Real Women Reveal the Sex Positions That Always Make Them Orgasm

Know the Moves
Once you have eased your finger into the area, moving it back-and-forth, like in a come hither motion, is a great way to stimulate the prostate. When a man gets stimulated it becomes easier to find because it swells up. Stimulating him with a generous reach-around, or while performing oral as your boyfriend requested, can put him over the edge. Once you get past the basics, you may want to try anal toys. Keep in mind, as an ER doctor friend of mine once said, "The butt is like a vacuum. Things that you put up there get sucked up." Therefore it is important when using toys for anal play that they are specifically designed for this area so they don't get "sucked up."

And this brings me to a common misconception about who, exactly, would enjoy this kind of thing. Recently I was on a radio show talking about this erogenous zone, and the male host was stunned that heterosexual men enjoy this activity. This thinking is very retrograde. As soon as he said that the call lines were flooded with straight guys raving about the orgasms that go along with this kind of play. Our bodies are meant to be explored and enjoyed through all kinds of stimulation. Whatever you and your partner are game to try and feel good about should be on the table. When it comes to sexual exploration, don't limit yourself to old ideas of what is acceptable and what is not. I encourage you to experiment, if your partner is interested; you just may give him the most intense orgasms of his life.