Grandpa Jack arrived on time to babysit his beautiful 13 year old granddaughter, Rachel. She really was growing up to be a very attractive, shapely teenager, with firm budding breasts and a cute ass. She answered the door when he rang the bell, all smiles with her pretty blue eyes and soft brown hair. She threw her arms around his ample waist in greeting.

'Whoa! Hey there minnow! Give an old man some room!' He laughed and she led him through into the house. Harry and Lisa, his daughter and her husband were ready to leave and promised to be back by midnight.

'No hurry. Now you two have a great time and don't worry about a thing.' 

For a while they played in the garden and then as the sun set and the evening cooled, they went inside and played cards. It was still warm inside the house and when Rachel came downstairs after getting ready for bed, she was only wearing a nightie and panties. Grandpa was watching the TV and didn't mind one bit when Rachel came and sat on his lap. She squirmed a little to get comfortable, her cute ass moving against his groin. He felt a stirring there, a sudden wave of lust that took him by surprise. His cock began to stiffen in his pants, almost against his will. He felt the hard flesh pushing against her. His mouth was dry and he felt a little breathless. She didn't seem to notice, her eyes fixed on the TV. He moved a little beneath her, felt his cock rub against her.

'You okay there, sweetheart?' He asked, moving a hand around her waist, close to the swell of her young breast. She wasn't wearing a bra. He began to stroke her gently with his fingers, his fingertips brushing against her nipple through the thin cotton of her nightdress. When she did not resist or question his actions he gently squeezed her nipple, feeling it stiffen beneath his touch.

'That feel good, honey?'

She nodded, not looking away from the TV. He could hardly believe this was happening. His cock was straining in his pants, so hard it hurt. He felt he had crossed whatever line he should not cross. He began to rock her gently, moving her young body against him, his breathing shallow. She seemed to enjoy the motion, moving with him, his dick pushing up between the crack of her ass. His other hand stroked her thigh, moving up beneath her nightdress, fingertips finding the soft cotton of her panties. He probed her gently, then his fingers teased the material aside, finding a covering of soft hair and her cunt lips, which were moist to his touch.

'You're my sweet girl,' he whispered into her ear. 'You like that honey?' He asked again, and again she nodded. By now he was fit to burst and gently eased her from his lap and removed her panties. She never said a word, but let him sit her down while knelt before her. She opened her legs and let him lick her there, his hot tongue probing her young cunt. He pulled her to him and lifted her legs so he could caress her asshole with his mouth, forcing his tongue into her. She squirmed and giggled, pulling her nightdress over her head, her firm young breasts crowned with hard, red nipples. He moved up her, undoing his pants, releasing his cock. His mouth ravaged her breasts, sucking and licking while his cock pushed against her virgin cunt. He entered her a little, then withdrew, held back by some restraint, some last thread of reason. He wormed a finger into her tight asshole, his mouth at last finding hers, then he was up and standing before her. He took her head in his hands and guided her mouth to his cock, rubbing pre-cum over her lips.

'Suck it now, sweetheart. There's a good girl.' She was unsure, but he pushed it against her young lips until she opened her mouth. 'Suck it gently now, sweetheart.' Her tongue flicked across his engorged head, teasing the slit. 'Just like sucking on a lolly, darling.' He pulled the foreskin back and forth until he could stand it no more. His cum exploded into her mouth, ran down her chin onto her breasts.

She was smiling up at him.

'That was fun!' She said.

'Well, let's get you cleaned up before mom and dad get home. And not a word to anyone . . .'