(A note for readers: Grandpa isn't a nice person; he wasn't meant to be. I may write a story with a nice grandfather, but do remember that this is a STORY, and that the characters are not real.)
Jenny did model the outfits for her mom. Well the three from the mall, anyway. Her mom complimented her on her taste and then headed to her room for a nap.
"Time to model for me, pet," her grandfather said as soon as her mom was in her bedroom. "Put on the red one."
Jenny had hoped for some time for herself, some time to enjoy her new clothes, but she knew she had to do what grandpa wanted. "OK," she said reluctantly.
"And strut like you're on the catwalk when you come out," he said as his pet went to her bedroom.
Jenny came out strutting as best she could, shifting her hips from side to side like a fashion model, and swinging the peignoir open to show the lace panties, bra, and garter belt she wore.
"Nice," grandpa said, "now turn around a few times, and then slide the gown off your shoulders for me."
Jenny complied, and grandpa began again. "Now bend over towards me so I can see how your tits hang in the cups."
"Very sweet," he said, whistling obscenely through his teeth, "now shake them."
His pet did as she was ordered, but she felt humiliated, like she was some kind of slut who had to... "I guess that's what I am anyway," she thought to herself.
"Come here, pet," he ordered, and she started to stand upright.
"No, stay bent over, just shuffle your way to my chair."
Jenny shuffled, realizing he wanted her breasts to continue to jiggle as she went to him. She stopped at his knees and stayed bent.