You go to the back, where the younger locksmith's expecting you

For a long moment you're frozen with indecision, then you make your choice. The younger guy will be easier to manipulate, you think, so you open the gate to the backyard, pausing around the corner to quell your nerves.

"I know you're there," the younger plumber calls. "I saw you when I was getting the keys. Come on out, I don't bite."

Reluctantly you peek out from around the corner, freezing as your eyes meet those of the young locksmith.

"Ooh yeah, as beautiful as the picture. Now come on out and let me see the rest of you. Too late to be bashful," he says, apparently thoroughly enjoying himself. And why shouldn't he? How often does he get to see a beautiful naked girl that's as hot as your sister.

Thinking of it that way somehow helps. It's not you he's staring at hungrily, it's your sister. She'd probably strut out there, showing it all, and flirt with him. Kind of like...

"Alright, you caught me," you say with a smirk and assuming an air of confidence you stroll out from behind the corner, all your goodies on display. "I was outside being a naughty girl and then you and your boss showed up."

You sigh theatrically, putting a hand to your forehead, which incidentally juts out your magnificent chest. "What's a girl got to do to convince a big strong man like you to let her in?"