Sexual tension is a social phenomenon that occurs when two individuals interact and one or both feel sexual desire, but the consummation is postponed or never happens. A common scenario is where the two individuals function in proximity, such as co-workers or in a group of friends, but do not have sex to avoid awkwardness or for other reasons.

Sexual tension can also occur when two individuals have previously had sexual relations and still feel an attraction towards each other, but do not wish to have sex again for fear of its effect on their current social situation—such as maintaining a relationship with a different partner. It can also be felt in situations when two individuals have a relationship devoid of physical contact, as in a long-distance relationship.

Sexual tension often occurs between individuals when the relationship is close and often flirtatious, yet the two people involved adamantly deny their feelings for each other. Meanwhile, it can appear extremely obvious to other friends or co-workers that such tension is present between the two individuals. When people give in to sexual tension, the relationship can become complicated and awkward if no new relationship level is established, as the relationship that existed before is no longer valid.