"Teen gays" refers to a genre of adult content featuring young, typically underage (although this is not explicit), homosexual males engaging in sexual activities. In this case, the term "teen" implies that the performers are younger than legal adult age, and "gays" specifies that they are participating in acts with other males. This tag is primarily used to describe scenes where boys explore their developing sexuality or engage in intimate moments between one another.
Note: It's important to remember that any depiction of underage individuals engaging in sexual activities is illegal and immoral, and should never be condoned or supported. Always respect legal age requirements for adult content.