Quick changing caught with consequences

The girls watched Timothy changing

For Timothy the hardest part of going out dressed as a girl was getting changed. He couldn't do it at home as someone might see him leave and once he was outside it was hard to find a quiet spot to change from Timothy to Tina. It was early evening and he wanted to spend some time out as a girl as he hadn't been able to for a few weeks and he was getting antsy. He walked around for a bit with his bag of girls' clothes until he found a quite corner of a car park behind a large supermarket. He looked around to make sure he was alone.

First he put on his long dark-haired wig. The sooner he looked like a girl the better. Quickly he took off his sweatshirt and jogging pants. Underneath he was wearing a white cotton bra and frilly white cotton panties. He chuckled to himself that if anyone saw now they would see a woman standing in a car park wearing only her undies. He pulled on a more feminine top and then pulled out the most important part of his costume, his new tight-fitting pants. There were white and he had been dying to wear them outside ever since he bought them. He pulled on the pants and tried to tug them up his smooth, hairless legs. He had bought a very tight pair and they were hard to get on but he loved the way they looked once he had them on. Timothy wiggled his hips from side to side as he pulled the pants up over his panties and at last they were in place. He gave them one final tug and then reached up to adjust his hair.
"Timmy, I think those pants are a size too small," a familiar voice said from behind him.
Timothy spun around and found his younger sisters Vicky and Mindy eying him up with cheeky smirks on their faces.

"Mind you he does have a very cute butt for a boy," giggled Vicky.
"He doesn't look like much of a boy to me," Mindy added. "Much more of a girl."
"We saw you hanging around looking suspicious so we thought we'd follow you," Vicky explained, talking in an exaggerated girly voice.. "I see we got here just in time. Anyway, we are going shopping for some clothes, would you like to come with Timmy?"
They burst out laughing at this and before the terrified Timmy could respond the two girls swept away.
"See you later Timmy," Vicky called out to him. "Oh, and for future reference, those white panties of your are giving you a terrible panty-line under those pants."
The girls shrieked even louder at this and Timothy could still hear them laughing and joking with each other all the way across the car park...