This porn video tag refers to a specific type of content where the scenes involve both older and younger gay male participants engaging in sexual activities. "Old and young" suggests there is an age gap between the participants, which might be a source of attraction or excitement for some viewers. The term "gay" specifies that these interactions are between males, not involving females. This tag may appeal to individuals who have specific preferences for age-gap relationships or age-reversal fantasies within the gay community.