You could hide, but why? Especially with that nubile young thing in the other room, and what you could do to her...
Elegantly, you step from the bath and stride to the door. "Young Miss? Please come here."
"Coming, ma'am."
You rest back in the tub, and wait patiently for the servant to arrive. She does, rather quickly. "Ma'am, how may I serve?"
"Scrub my body. Thoroughly."
She reacts without hesitation, taking up the brush before you stop her. "With your tongue."
Was that a hint of a smile? "At once, ma'am."
Intantly, she responds, working along your back and neck with her tongue. You moan as the mass erogenous zone that is your newly demonized body is teased to perfection. By the time she reaches your wet breasts, you are reeling on the cusp of orgasm.
"Take off your clothes," you throatily whisper, your voice a stern and unavoidable command.
Your servant obeys, stripping herself and allowing her body to be led into the tub.
"Now, clean my mouth." She does, kissing you deeply as she begins to sigh. You let your form slip, beginning with your tongue and tail. She tenses, and you would fear her flight if not for your strength.
You break the kiss, only for a moment, and let her view your true form. "Say you will serve me forever." You punctuate the command with a wiggle of your tail along her slit.
A sigh emanates from the servant girl, as she works to get your length inside her. "I am yours, Mistress."
With that, you plunge your cock tail inside her, giving her rough riding as you take her tongue once more. This time, however, you bite down, feeling something leave your gums and enter her bloodstream as she gasps in pain.
"Shh, you'll like this," you whisper, still rutting her with your appendage. Every bodily imperfection fades as breasts inflate and ass tightens to luscious, fuckable perfection. She reels and nearly faints as her skin reddens and a swollen tongue grows thin and forked. Small horns bud from her forehead as she scrambles for the sides of the tub with her curling claws.
You laugh proudly. Eyes of red with slit pupils gaze upon you, and she hisses through her own set of lengthening fangs as she rides your tail to one climax after another. A tail of her own buds from her spine, forming a perfect phallic tip as it grows to a serpentine five feet. She grows no wings; as a mere servant, she'll have no need for them.
"Thank you, Mistressss," she hisses, lowering her head in respect. "I will sssserve you alwayssss."
"Yes, you shall. Now then, I shall call you Alexis, because the name pleases me."
"What pleasssessss you pleassssessss me, Missstresssss."
You grin wickedly. You're going to enjoy this.