They could hear Mandy's grandmother storming up the steps. It was too late to hide their condition. They weren't all completely dressed and she would know what was going on for sure.
Mandy quickly placed the mask back on her face and pulled her father under the covers with her. Mandy's grandfather Kirk, who was the most dressed of the trio, just had time to zip up his pants before the door burst open.
"Oh my god Fred!" Mandy's grandmother accosted him. "Is sex with young bimbos all you think about since the divorce?" Mandy's look of disgust didn't go unnoticed by her grandmother.
"What if Mandy had come home early and seen this?" She asked. "How would you explain that you were having sex with a girl this young?"
Kirk chimed in. "Honey, can't you just let Fred be happy for once in his life?"
"I bet you you're only angry cause you really want to watch us don't you?" Mandy added. Her grandmother was mortified at the thought. Mandy was so angry with her grandmother for insulting her father, her new lover,that way that she didn't care anymore. She yanked the covers off of her father and reached into his half-on pajamas, pulling his cock out into the open.
As her grandmother gasped in horror, Mandy leaned over and sucked her father into her mouth yet again. She expertly worked her lips over the shaft, running her tongue along the sensitive underside of his cock. She loved her father's cock and it showed in the way she serviced him.
Mandy's grandmother, though horrified, was unable to move. Kirk moved his eyes from the erotic scene on the bed to his wife and then back again. He wondered how far he could take this. Mandy had awakened erotic, sexual feelings that Kirk didn't know he possessed and that he was incapable of controlling.
Drool was leaking out of Mandy's mouth every time she came up for air. Then she would work her lips down to his belly again burying her father's cock deep within her throat. Fred had no desire to let his mother see him cum but knew that he was helpless to control his daughter.
Mandy had been sucking her father for some time and decided she had to see the effect that it was having on her grandmother. She glanced over and she froze. Her grandmother had dropped to her knees and was slurping on Kirk's cock with wild abandon.
Mandy released her father's cock from her mouth with a wet pop and nudged his shoulder. "What?" he said as he sat bolt upright in the bed.