Passion of Injustice - Undyne x (Female)Reader

Quiet Water - Sort Of

You eventually uncurled from your fetal position, but you remained in that very corner until the hour she marched from her room clad in full armor.
You couldn't even bring yourself to look up from the floor.

Your peripheral vision told you that she was looking right at you, before shielding her entire head in her helmet.
You thought she wasn't going to say anything.

"Stay here. I'm going for a mandatory patrol" she coldly ordered.

The chill to her voice was so unlike her. Normally, she was very fiery and over-the-top, but she was like ice.
This bothered you immensely.

You had opened your mouth to say something, but she had already left.

Now you're re-evaluating everything. Your life, your thinking - how you're going to approach Undyne and prove your worth.
You're so bored, you have nothing to do but to think.

You've already explored around the house, trying to find something to keep you busy. You feel as though you can't go through with a truly thorough search however, as you'd feel invasive potentially digging around somewhere she didn't want you to be.

You consider playing around with the piano yourself. Perhaps it would be entertaining to create your own music by ear like you used to do.
What if another monster passes Undyne's home and hears you playing while she's out though?
You decide not to play.

Looking down at your arm, you stare at the gash from the last time she tried to kill you. She had dressed the wound, but when you ran away in a hurried fit, the bandages had slipped off. The dirt had gotten into it and it looked nasty.
To be truthful, you feel over all kind of nasty. In your flesh, as well as in your mind. After running around the Underground since you jumped, it has been so long since you last bathed or showered.
Your hair's greasy, and your skin's covered in a thin film of dried sweat.
You'd felt a little bit bad for lying in Undyne's bed while being so filthy.

Suddenly, you decide what you'd like to do.
You're going to freshen up for Undyne.

You weakly stand up and scale the house one more time for the bathroom. You hadn't managed to find it earlier, but you know it's got to be around somewhere.

You inspect the whole layout probably 4-6 times over, yet still - no bathroom.

Well, surely as a living organism, she has certain bodily functions, right?
You wonder if perhaps the differences between humans and monsters were a bit more plentiful than first gathered.
You're still puzzled as to how this conclusion is biologically possible, but the whole Underground is mysterious enough for anything to be possible.
Kind of like the deep sea.

You chuckle remembering the coincidence that Undyne is a fish type. It feels good to be amused by something...

An idea strikes you. Perhaps there's a body of water outside near enough for you to bathe without Undyne scolding you later for wandering off - again.
Hopefully it's secluded enough so that other monsters won't spot you. Not only because you're human, but because you'll be a naked human - and you're naturally a bit shy with that sort of thing.

You decide to exit the home in the most discrete way possible. You enter Undyne's bedroom and see the window off to your left. Since this room is comparatively further back from potential public eye, you figure no one will notice you crawling out of the wall this way.
Moving forward, you gently pry open the window and then stagger your leg out, following with the rest of your body.
You harmlessly land on your feet, as the drop was nothing, and begin to scan the area.

Stalking closer to the very back of the house, you find exactly what you were looking for:
An entirely undiscovered spring and pool of water, closed off to the rest of Waterfall by a mouth of cave-like walls.
There are numerous large rocks here and there to jump behind in case you need to hide. In actuality, these rocks look more like mini mountains to you.
A few of those light-up mushrooms you've spotted around the premises of Waterfall decorate the floor of this cavern, keeping your surroundings well lit much like the water- which is blue, clean, clear, and glowing.
You can see the reflection of the swaying ripples cast onto the ceiling, which illuminates the thousands of crystals there as if they were stars in a midnight sky.