"Oh, Grandpa, you're such a perv!" said Sandy, laughing, after Grandpa had regaled her and her two sisters in the car with more of his anal exploits.
And it was true, Grandpa
is
a perv. He knew all his granddaughters' birthdays by heart because he had patiently waited until they each turned 18 to assault them and take their anal virginity. They called it Grandpa's birthday present.
Sandy is the youngest, so she was prepared by her older sisters for what was to happen the day she turned 18. The same thing had happened to their mom, but Grandpa now preferred his granddaughters. They would take turns servicing him and convinced him to allow them one day off a week, which meant that each girl would get fucked in the ass by Grandpa twice a week.
Sandy thought back on the night she turned 18. Grandpa came into her room at night and lay down next to her, completely nude. Sandy was on her side with Grandpa behind her. He raised her nightie and began fondling her ass. Before long, he separated her cheeks and began rubbing his finger against her asshole. He squirted some lube on his finger and inserted it up her bum. All the while he was telling her how much she was going to enjoy it, that it was the sexiest feeling she would ever have.
Her sisters had taught Sandy how to masturbate and she did that regularly, but no one had ever fucked her in the ass before.
Grandpa added another finger and was pushing his fingers all the way in and then slid them in and out. Sandy had been told by her sisters that the first time hurt a lot, but so far it didn't. Grandpa told Sandy to touch herself, which she took to mean, to masturbate. She began to rub two fingers in her crack, alongside her clit.
Then Grandpa removed his fingers and Sandy felt his erection against her nasty hole. It was so big! Grandpa lubed his cock and her ass again and slowly, very slowly, began pushing it inside her. He would push it in a little way, then take it out. He did this over and over and slowly her hole began to stretch and he was able to push it in a little more. Finally, her sphincter gave way, allowing his cock to slide all the way in.
Oof! It felt so big inside her. It was unlike anything she had ever felt before, so full. It hurt, but it wasn't unbearable. Grandpa had been so gentle. It had taken a good 10 minutes to get to this point. Grandpa held still and so did Sandy, waiting for her ass to adjust to the feeling of his big cock inside her. Slowly, Grandpa began sliding is cock out until it was almost out of her, then he would slowly slide it back in.
He began to pick up his tempo, pumping in and out, faster and faster. Sandy also began frigging her cunt harder and faster. The pain she felt was exciting and sexy. Her whole erogenous zone from her pussy to her ass was on fire with feeling, pain and pleasure. As the feeling of Grandpa fucking her ass grew, Sandy reached a point of no return. She knew she was going to cum any second now.
Grandpa thrust all the way into Sandy. She could feel his balls slapping against her ass. He groaned and held her in place by her hips as his orgasm exploded in her ass. She could feel his cum filling her ass. Sandy exploded at that moment, bucking and groaning as she came. Both collapsed on the bed as they recovered from their orgasms. Grandpa's penis slowly deflated and he let it fall out of Sandy's ass.
He scooted down and pulled her cheeks apart to admire her gape, her deflowering. A big glob of cum dripped out of her ass. Grandpa took it on his finger and pushed it into Sandy's mouth.
"Drink that," he ordered. Sandy tasted his salty cum mixed with her ass juices and lube. She swallowed. It wasn't so bad.
"You're my ass whore now," Grandpa said.
The next day, Sandy's sisters, Helen and Irene, gathered around to find out how it was.
"It wasn't so bad," Sandy told them. "He was gentle and took his time. It hurt, but it was also exciting. I couldn't believe how big Grandpa's cock is, though."
Helen and Irene told Sandy that it would become less and less painful until it didn't hurt at all. They said that they both had thought it would be gross and that they would never accept sex that way, but now it was their favorite way to have sex.