Do you fantasize about threesomes? You aren't alone. Threesomes are by far the most common sexual fantasy for both men and women of all sexual orientations. But while the fantasy of a threesome might be incredibly arousing, the reality of the sex mechanics can be a bit more tricky.

By popular demand, we've put together the ultimate guide to threesomes, designed to help you avoid emotional fallout and damage to your primary relationship. After all, no amount of pleasure is worth months of drama.

Follow this guide, and you'll know how to have a hot, successful threesome. Or you may discover that you should just keep the ideas as a hot fantasy — the choice is yours.

Why are threesomes so hot? There isn't a whole lot of mystery to it: if sex with one person is exciting, why not double the pleasure?

Many people fantasize about the thrill of adding someone new to a long-term relationship, but novelty alone is usually not at the heart of the threesome fantasy. Threesomes are very much about the experience of multiple lovers at once.

Here are some of the most common reasons the threesome is such a popular sexual fantasy:

There's endless variety. Three mouths, six hands, and three sets of genitals offer an endless array of combinations. Specific combinations depend on the genitals involved and the boundaries of each particular threesome. Many people have specific combinations that they find especially thrilling.

Three mouths, six hands, and three sets of genitals offer an endless array of combinations. Specific combinations depend on the genitals involved and the boundaries of each particular threesome. Many people have specific combinations that they find especially thrilling. There's more of a good thing. Like breasts? How about four at a time? Love the sensation of hard muscular arms? Try being surrounded by man flesh. Many people love the idea of doubling their pleasure with multiples of a body part they're particularly fond of.

Like breasts? How about four at a time? Love the sensation of hard muscular arms? Try being surrounded by man flesh. Many people love the idea of doubling their pleasure with multiples of a body part they're particularly fond of. Adding another person is riveting. If having sex with one delicious lover is confirmation of your desirability and sensuality, being sexual with two people can make you feel like a sex god or goddess. It can be very thrilling to turn on not one but two lovers.

If having sex with one delicious lover is confirmation of your desirability and sensuality, being sexual with two people can make you feel like a sex god or goddess. It can be very thrilling to turn on not one but two lovers. You see your lover anew. Threesomes give you the opportunity to see your lover with someone else, and this encourages you to take a step back and witness your lover with fresh eyes. Many report seeing their lover with all new appreciation and heightened desire. While not a solution for a relationship that has gone stale, threesomes can reinvigorate a successful but complacent relationship and renew your love for one another. (They could also destroy a relationship, so it's important to be on the same page as your partner.)

Threesomes give you the opportunity to see your lover with someone else, and this encourages you to take a step back and witness your lover with fresh eyes. Many report seeing their lover with all new appreciation and heightened desire. While not a solution for a relationship that has gone stale, threesomes can reinvigorate a successful but complacent relationship and renew your love for one another. (They could also destroy a relationship, so it's important to be on the same page as your partner.) Same-sex experiences become reality. For many people, a threesome is a very safe way to explore what it's like to share erotic energy with someone of the same sex. For many straight people, a threesome is the first place they experience same-sex erotic contact. Many people who think they won't have much charge with a same-sex lover discover that there's actually a lot of potential for pleasure where before they had seen none.

But beware: Bad experiences in threesomes can cause oceans of resent and regret. Great threesomes can be absolutely amazing. Here's how to have a successful threesome and avoid any hurt feelings.

1. Ensure that sure all participants are involved.

A great threesome is something so much more than typical sex with two people; it creates a triangle formation of erotic energy, amplifying every part of the experience. A good threesome isn't "first you, then the other;" it's all three people engaging together, pooling their three sources of erotic energy into a common experience. When this works, it can be incredibly powerful and an experience you cannot reach any other way.

The caveat: when the energy isn't flowing between all three people, the connection between any two is compromised. If two people on the bed are consumed with one another and the third is sitting there feeling left out, the net experience will be less than the two people could create alone.

As a general guideline, if you're going to have a threesome, make sure to include the participation of all three people. Go to great lengths to make sure no one feels "left out."

2. Choose your partners wisely.

Many people wonder if they should have a threesome with a friend or a stranger. There are benefits and risks to both. Strangers provide less risk for long-term emotional fallout, but higher risk for personal safety. Inviting a friend into a threesome is more emotionally charged, but can feel safer. Plus, if it's successful, you may be able to repeat the fun over the years.

Don't have a threesome with an ex-lover or your best friend; the emotional risks are far too great. For most people, the best choice is someone you know and trust, but who doesn't play a pivotal role in your life.

3. Make sure everyone involved is erotically excited by everyone else.

This is especially important if sexual orientation is an issue. The same-sex contact in any given threesome can range from very little physical contact to full lovemaking and penetration. But the "no-touch between us guys; we are just here for the woman" threesomes tend to fail miserably.

If you're so invested in not touching someone, you probably shouldn't do a threesome together. The success of your threesome depends on your attitudes, so make sure everyone has an open mind and open heart. Discuss all of this ahead of time so expectations are clear and boundaries are firmly established before you dive in.

4. Expand your definition of sex.

It can be incredibly thrilling to have a threesome that doesn't include intercourse. You don't need to go "all the way" to enjoy all of the benefits of a threesome. Consider starting your threesome explorations with agreeing to stick to non-penetrative sex. Using your hands to give one another pleasure is both super-hot and safe.

You can still explore the intense sensations and erotic potential of three naked bodies in bed together, but without all the emotional and physical risk of intercourse. This "starter" threesome can be a good way to explore at first, and if it works for you emotionally and physically, you can always go further next time.

5. Always keep things safe.

Safe sex is always essential, but if you're bringing a new partner into an established relationship, you'll want to refresh your commitment to safe sex practices. You won't be able to relax and enjoy yourself if you're worried about contracting a disease or an unwanted pregnancy.

Make sure all three of you are on the same page about safe sex. And buy extra condoms, dams and gloves. You may go through a lot during a successful threesome.

So should you have a threesome or just keep fantasizing about it? For many people, the fantasy of a threesome is enough. Other folks name threesomes an intense desire, and want to make it a reality.

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Only you (and your lover) can determine if this is best left as a fantasy alone, or if you want to explore it in the flesh. Here's a series of baby steps you can take to explore your threesome fantasy.