Granny is calling - Short story

A week after grandmother went home, the telephone is ringing. Mother answers it.
Her mother, Peters grandmother, is on the phone. Both women talk for a while till granny asks if Peter could come over and help her around the house. Sure, his mother answers, and a few minutes later the two finish their talk. Mother goes to Peters room and tells him about the phone call.
Next day the boy gets on his bike and drives to his grandmother. She is outside, already waiting for him. The woman asks Peter to come in and offers him something to drink. They are in the kitchen and both sit down and talk.
Grandmother says that she was missing the boy and his cock. She enjoyed the fucking with her grandson and wants to do it again. Of course she couldn`t say that on the phone!
While she is telling that, granny gets up and pulls her dress over the head. Then she opens her bra and gets rid of it. All she has on now is her panty.
"What are you waiting for" she asks with a smile. "Get off your clothes".
Peter gets naked and his grandmother pulls him in her bedroom. There she takes off her panty. The two get in bed and fuck all afternoon. Finally the older woman has to stop. She can`t stand it any longer. Her cunt isn`t used to fuck that long and much anymore.
"I`m sorry", granny says. "The fucking with you was fantastic and I hope we do it again".
"We will. For sure", Peter answers. Then he gets up, puts on his clothes and leaves home after giving his grandmother a tight kiss.