What does it mean to tongue wrestling in gay sex?

What is tongue wrestling ?

A deep and prolonged kiss between two people, where the tongues are constantly going in and out of each other's mouths.

About

Not everyone is into kissing, though many will engage in it, as a form of foreplay, that allows for the hands to explore the body of the person, they are kissing.

In reference to an extremely passionate form of kissing, versus a normal kiss.