The Alpha's Baby by M.E. James

At first he just added one, then he plunged his digits in and out of her hole. The sensation burned in the beginning, but as he increased his speed, she arched her back and wriggled her hips as she began to enjoy his touch more and more. After she lost track of time, he finally pulled his fingers from her ass.
    "I think you're ready," he purred, stroking her ass cheek.
    With his cock dripping from her juices, he eased his way into her, stretching the tight hole to the max. She sucked in air as he entered her body, certain that she was going to explode from the pressure in her ass. Once he was inside of her all the way, he cupped her breasts again and squeezed a nipple between his fingers.
    "I'm in you," he whispered. "I'm in your ass."
    She groaned in affirmation, aroused because of his words.
    In one swift motion, Sebastian plunged inside of her again. As he quickened his movements, he fondled her sensitive nipples. She became certain that she was going to explode. While she cried out his name, she arched her back, presenting her rear end for him to impale deeper and deeper. His balls began to slap wildly against her cheeks, and his rhythmic grunts filled the air.
    "Yes," she cried as she neared yet another orgasm.
    His answer was a thrust so hard that it sent pleasure spiraling throughout every inch of her body. She wailed his name, unhinged by her own yearning. She wanted—no, she needed—to be ridden, and her cries marked her unrelenting urgency. As he gave her everything he had, he brought his hands down to her ass and squeezed her cheeks together. While he took her, the sensation of his hardened rod thrusting inside of her drove her to orgasm one final time.
    "Oh God, I'm coming." She bucked as he rammed himself inside of her yet again.
    The orgasm she had was so powerful her legs weakened and she almost slipped to the floor. She was grateful that she didn't lose her footing because Sebastian had yet to come. But after one final grunt, that changed. The man seized her hips and emptied himself inside of her quivering body.
    As he filled her ass with his seed, she whimpered, "Sebastian," and reached for him.
    Even as he trembled from his overpowering orgasm, he caught her hand and held it. Pulling her close, he placed his hands on her heaving chest and buried his face in her neck. She could feel the man quaking against her, and she leaned back as the urge to be closer to him grew. The man nestled his head in her neck, then laid a kiss against her throbbing vein.
    After a moment of closeness, he sighed. "You were amazing."
    "Mmm." She opened her eyes. "I think you were the amazing one."
    He spun her around so she faced him.
    "Why don't we compromise and say that we're amazing together?" The roguish sparkle was back in his eyes.
    She grinned. "You know what, I think that's something I can live with."
    Nodding, he bent his head and captured her lips again.
    That was the moment she felt her heart stir for the first time.

Chapter Four
     
    When Emmy opened her eyes the next morning, she discovered that there was an arm draped over her chest. And not just any arm. A hairy, muscular arm. She stared down at the limb, thinking that she was going crazy, and then remembered what had happened the night before. Sebastian had once again seduced her, and then she'd ended up having butt sex with him in the shower. She had no idea how he'd managed to get her to try anal. One second she was a vanilla woman who'd never had any desire to have something shoved up her ass, and the next, she was being taken from behind. She never did things like that. What was it about him that made her want to delve into the unknown?
    That was the moment when she realized something. She trusted Sebastian. That was why she'd let him do what he did.
    Maybe it was strange to have such a philosophical thought all because she'd been speared up the corn hole, but she couldn't think of any other reason why she would let a man shove something up her rear end.