Bitten

Sarah was walking home from work late one night. The full moon shone bright in the sky, Sarah pulled her jacket closer around her shoulders. "Boy it sure seems creepy tonight", thought Sarah.
Suddenly, something shot out of the darkness and pinned Sarah to the ground.Breathing on her face, the creature lunged and Sarah's world went black.
When she came to, she was still lying in the same place. "What the heck was that", thought Sarah. She tried to get up but was forced back down again by a splitting pain in her shoulder. When she slid off her jacket and shirt and looked, there was a massive bite mark on her shoulder. "How did that happen?" she thought as she slipped her shirt and jacket back on. Some time later, the pain subsided and she stood up and caught a bus back to the apartment she shared with her boyfriend.
When she arrived back, her boyfriend, Alex jogged up to her, he was a fitness fanatic, and asked, "where were you last night,babe?". To this, Sarah replied "I got knocked out by some freak with really bad breath, and then something bit me real bad". "Oh well, I'll make it up to you tonight", said Alex.
That night, they stripped down to their underwear and got out the neccessities.
"First, let's let a little light in, it makes it more romantic", said Alex, tearing open the curtains, letting the light from the full moon. As soon as that light hit Sarah, she felt a funny tingling all over her body, then it became a slight pain, then an urge to be free. She tore off every strip of clothing thagt she had on, exposing her naked body to the moonlight. "Babe", whispered Alex as Sarah's body started to change.First, she felt a pushing sensation as four new breasts extended out from under her original ones, then, she was racked with pain as her spine extended and she grew two feet taller. Then, her nails and toenails spilt in half, revealing shiny black claws. After that, her ears migrated the top of her head and grew into points, and her mouth became a muzzle and her teeth became razor-sharp. Finally, snow white hair began to sprout everywhere on her body, and her muscles balooned. There she stood, a proper werewolf. She looked at the startled Alex and had not an urge to hurt him, but an urge to mate with him. She rushed at him, making him yell, then pushed him over and straddled him, pushing herself onto him. Only then did Alex realise what was happening, and for a few moments, he enjoyed it, then his face turned white as snow, and Sarah felt something being pushed into him.Then the same changes started happening to Alex, but Sarah felt his cock extend an extra foot into her. Then the two werewolves had a very enjoyable night.
The nexat morning, Sarah woke up lying naked in bed, with Alex lying next to her, grinning. "Good morning, babe", said Alex leaning in to kiss her. But, they met before their lips met, and they looked under the duvet to see that they had both gained at least 100 pounds. "Oh well", said Alex, "I'd sacrifice fitness for what we did any day". A week later, the new, fat, werewolf Sarah tested positive for pregnancy, and smiled, they were going to have a family, and they were going to hunt...