A Driving Urge
Beyond a biological imperative to protect and claim. beyond the carnal desire for companionship and a virile breeding partner. beyond even the loyalty of repeated mateship and the raising of litters as parents.
Mr Smith Finds Room for Two
It was a biological imperative. it was very nearly the driving force in his life, whether he recognized it or not. he sucked in a breath. he suddenly felt a presence inside him that was very unfamiliar.
Human raptor breeding program-short story
The knot at the base of his shaft locked in was a constant, unyielding presence, a reminder of the biological imperative that had brought them together.
Ryan's Story Part XV
"yes, i remember sulvius saying something about a biological imperative to snoop." tanner laughed. "that sounds about right! cats have nothing on dragons for curiosity."
Traveling Salesman (Of a Sort)
Something had to be going on here, because there are heat cycles and strong heat cycles but the amount of biological imperative trying to convince me to breed this fox combined with the overpowering smell of female arousal was making it seem like i had four
Heat Cycle
"you're just carrying out the biological imperative coded into your genes. you don't need to apologize.
Forest Keep 11
The surge of hormones diminishing as her biological imperative was fulfilled. finally able to think clearly she licked james on the chin, watching him grin up at her "wow", was all he could say before kissing her once more, "how do you feel?"
Beak and Claw
He had achieved his biological imperative, his drive as a man... and now he was going to impart his blessing to his sons. father thrust as deeply as he could go, ramming tight and hard and holding himself there.
The Cycle
But she did not want to give into a 'biological' imperative; if she was going to mate she wanted it to be for love. she wanted to have a child made from a joining with some one she loved and wanted to have.
Blessing of the Satyr Part 1
He only cared about one biological imperative. damon needed to cum. now. he felt a wave of euphoria crash into him and a thick, white, and creamy jet shot forth from his member!
Cloud Seeding
Once released they will do all they can to deliver their chromosomal package into a host, it’s their biological imperative.” faces looked back and forth, but all landed on the rabbit at the centre of the room.
Centerpiece
Brushing furiously at her tail in an attempt to soothe her nerves, erin let a stony silence fall, fighting to sort out a turbulent mixture of embarrassment, arousal, and that longing she'd always associated with her drive towards motherhood, biological imperative