See a stranger in the bar and immediately feel a spark. The rest of the environment disappears for a moment. Suddenly your knees move uncontrollably. It's like there's a magnetic attraction between you, a vibration you can almost feel in the air.

Situations like these appear prominently in the beautiful dating stories of happy couples. But sexual tension isn't just on first dates, even people in long-term relationships can still experience this feeling with their partners.

Simply put, "sexual tension can be the secret ingredient that distinguishes a good relationship ," says Nazanin Moali, PhD, a certified sex therapist.

And while sexual tension can be positive and make the relationship stronger, especially when the feeling is mutual, you may find yourself in situations where you experience sexual tension that probably shouldn't be acted upon. Especially considering one's relationship status or other circumstances.

What exactly is sexual tension?

"Sexual tension occurs when one or both people experience sexual attraction; however, they do not act on these desires, " says Moali. "Essentially, sexual tension is all the feelings and actions that constitute 'waiting for attack.'

How do I know if I'm experiencing sexual tension?

Everyone is different, but some common physiological signs of sexual tension include flushing, dilated pupils, rapid heart rate, muscle tightness.

In addition to physical signs, there are also mental signs. Psychological signs may include an inability to concentrate, increased self-consciousness, and being preoccupied with the other person.

You may be thinking to yourself, “Well, these seem like the same traits as anxiety. How do I understand what I'm experiencing?"

Anxiety and tension have many similarities in symptoms, so it can be complicated. But to clarify the sensations you need to keep something in mind:

Even if you feel sexual attraction or tension, it does not mean that the feeling is mutual.

The key is to reflect not only on how you feel, but also on the signals from the other person. Does it look as flirtatious? Does he approach you, touching you at random moments during the conversation?

These signals can help determine if you're both on the same page, and that's key to figuring out what to do next.