Everyone's libido is different. Some people have a stronger libido than others and therefore crave sexual activity more often. If you desire more sexual activity than your partner, or than other people you know, that does not automatically mean you have sex addiction, although it could be one sign. If you suspect you may have a problem with sex addiction, ask yourself whether you also experience these other more reliable indications that therapy is needed.

You have risky sex with multiple people.

There is such a thing as non-problematic, non-monogamous sex between consenting adults. However, if you are having risky sex with multiple individuals, this could be a sign of sex addiction. (Risky sex is sex without protection, or with individuals who you know may not be safe to interact with in this way.) Since you know the risks and choose to engage in the behavior anyways, this shows a lack of self-control that often comes with addiction and could indicate that you need counseling to help you regain that control and make wiser choices in the future.

You habitually masturbate.

Again, masturbation can be healthy. Some people even masturbate several times per day without it being a symptom of addiction; this is especially common in younger adults. What you need to think about, however, is how you feel when you can't masturbate for a day or more. Do you feel an overwhelming unease if you can't engage in this behavior? Has masturbating become such a habit that you find yourself unable to go without doing it for even a day? If so, this may be a sign of addiction.

You cheat on your partner repeatedly.

People cheat for many reasons. Sometimes cheating is simply a sign that you're not happy in your relationship and need to move on. But what if you are happy in your relationship, and yet, you cannot stop yourself from cheating again and again? This can wreak havoc on your personal life, which you probably know, and it is also a key sign of sex addiction. 

You're more interested in sex than anything else.

Do you have trouble focusing on work, school work, or other responsibilities because you're only thinking about sex? Maybe you have even lost your job or earned poor marks in class because of this. Feeling like you "can't turn it off" in this way is another sign you need to seek out sex addiction counseling.