Part of Ethical Non-Monogamous Relationships. Refer to a man with hyper masculine traits, behavior and unusually high sexual stamina who engages in sexual activities with one of the people inside of a committed relationship [female or male]. The person with whom a bull has sex is usually the Cuckoldress or the Queanbull within the relationship; they can also be a third party in a Vixen/Stag dynamic. In a cuckolding dynamic a bull plays the role of a more potent and skilled partner for the Cuckoldress in order to humiliate the cuckold, in a Vixen/Stag dynamic there's no such humiliation factor involved.