Sword fighting is an activity in which two people slap their penises together, much as sword fighters connect their swords during a duel.
Sword fighting participants are typically assumed to be gay or bisexual males, but it is also reported among men who identify as straight. Because there is limited data on this practice, it's hard to determine how common sword fighting really is. Sword fighting is also common in gay pornography.
Sword fighting is sometimes called swashbuckling.