In the role of dominant, with couples, especially inexperienced couples, I encountered a few reluctant wives (and more reluctant husbands).
Most of the time, the reluctant wife was basically overcome with lust and desire, once she saw my hard cock. It was effortless from that moment on, with the reluctance fading to sex-crazed madness as things progressed from hands, to lips and tongue, mouth, pussy, and ass...
During one encounter, I sealed the deal by putting on a masturbation show for the reluctant, timid wife. With her seated in the hotel room's desk chair, I stood completely naked, standing between her knees, slowly jacking my cock, inches from her face. I watched her face and eyes, looking for a certain glassy-eyed, "I'm losing it" expression - the look of her giving over to desire from reluctance. When I saw that cue, I moved closer, touching her lips with just the tip of my cock, until her tongue responded, wetting the glans, finally fully entering her mouth. After a few minutes of ever-more enthusiastic sucking, she was dripping wet, and ready to be fucked.
Voluntarily, she rose from the chair, got onto the hotel bed, hands-and-knees, lifted the hem of her dress, and demanded that I fuck her. I did that little honey every way I could think of while her husband watched, alternating from his face in his palms, gasping, trying not to look, to slack-jawed, bug-eyed, as his little wife bounced up and down on my cock, squealing like a kid on a pony.