As far as run-of-the-mill erotica goes, there are plenty of titles out there (some I've even pubbed) where "dubious consent" is used as a tag to tell readers there is some element at play in the work where at least one of the characters does not initially agree to the sexual advances of others, but winds up giving some form of consent before it's all said and done.
The line between dubious consent and nonconsensual is very thin. Going too far can get a work (or even an entire series) banned from one of the distributors.
Since I don't mind holding my hand over the fire from time to time, I've recently pubbed a sequel to my series "Taken for a Ride". It's the story of a young med student named Terry Givings that gets her weekly thrill and break from monotony by hanging out at a local bar frequented by bikers and other "rough" characters. She is entranced by one man in particular- Raul Julian, the president of the biker gang Brothers of Street. One thing leads to another and before she knows it he has her up against a wall and making her his submissive slut.
In the sequel, Raul has left her alone in her apartment and she finds herself confronted by three thugs from a rival biker gang, Dios Elegir, or God's Elect. They are a gang backed by The Cartel in Mexico and have no reservations about protecting their territory, and that includes flushing out and doing whatever it takes to bring down The Brothers of Street. When they invade Terry's home, she's left with little choice other than to do what they want.
Taken for a Ride 2 is now available at all distributors.