Undercover niece, not brother

"Walter, you are overly excited you are going to give yourself away in the first 5mn - you are incapable of keeping up this pipsqueak voice which doesn't even sound like Tina. Trying it with your machine is too risky with the teething troubles but I have the solution. Get your machine to adapt your body to have a condition called Puberphonia , no don't start looking it up. You are my niece and you would obey me and not start doing crazy inventions like Walter."

As WalterTina programmed the device s/he hesitated a second before pushing apply looking at her/his wife/aunt with pleading eyes coupled with an impatient and impertinent little huff and eye roll.

"You will have to trust me, just set it to expire in a few hours if you want to be safe. This is not as simple as that film, Undercover Brother you like so much where a white man pretends to be a black one. Being a woman is a core part of your being and you must live it as well as sound like it. Now young LADY do it so we can get to the BBQ. " Rebecca's eyes narrowed as they only did when she was really cross and WalterTina quickly applied the condition. Nothing felt different except for a slight constriction in the throat.

"This didn't do anything Becca." Which caused Rebecca to burst out laughing because the voice was no longer Walter's gruff male one but a slightly breathy falsetto young boy's tenor voice. Totally appropriate for a throaty but late adolescent woman - it may not be Tina's natural voice but it didn't sound off. WalterTina was slightly disconcerted - unable to field her normally deep baritone commanding voice, s/he might find that if the situation got sticky she couldn't bark her way out of it. Tina's slim youthful body might be fast but would be no match for any of the men there - a sense of vulnerability and fear flashed briefly through her frame.

"Let's go Tina, follow me." and she did.