Jason by Laurell K. Hamilton — book slip

Jason Schuyler, one of Anita Blake's closest friends and a werewolf, is in a non-monogamous relationship with J.J., a talented ballet dancer. J.J. is bisexual and plans to continue her relationships with women, while Jason seeks to fulfill his need for rough sex and bondage elsewhere. To help J.J. understand his needs, Jason enlists Anita's help, leading to a complex web of relationships and desires.

Part of the Anita Blake, Vampire Hunter series.