In the context of human sexual behaviour , especially anal sex among gay men, a top is an insertive partner, or a person who prefers the insertive role. The counterpart is a bottom .
"Top" can also be used as a transitive verb meaning to sexually penetrate.
It is very commonplace for partners to change roles from one encounter to the next or to have both insertive and receptive sex, although many people have a preference between roles. A person who enjoys both topping and bottoming is called a switch or versatile . In Singapore, the term is flexible .
The terms "dominant" or "active" have been used for "top," though these may be confusing as the sex in question needn't be part of a dominance relationship, nor is the bottom necessarily "inactive."
By extension, the term "top" is also used in BDSM to mean a partner who applies stimulation to another, and who may or may not be dominant . See top (BDSM) .
Tops sometimes identify themselves by wearing a set of keys on the left side of the belt or a colour-coded handkerchief in their left rear pocket. This practice, called flagging , began in the gay male subculture but appears to be dying out.
In sexually-themed anime and manga , especially shounen-ai and yaoi, a top is referred to as seme , a term from kabuki.