"Damn French and their incompetent maintenance. We've been stuck here for over an hour."
"Girls, we're not getting down any time soon and I really need to pee."

addition to the previous scene

Waht you are showing here is excellent, many thanks!!

I have worked with Daz 3D for myself, and it really makes much fun to find out how to built such scenes. correct. I have huge problems to show pulled down pants correct. What looked so natural in your pictures are a catastrophe in my work...

Doing pants pulled down in Daz Studio is a bit of a pain in the ass and takes some practice. Some pants have a morph for that, or you can use the fit control product, but that usually only works in the standing position.
So here's the trick I use that works with almost all pants:
1)Fit the pants to the girl and put the girl in the pose you want.
2)Change the "fit to mode" of the pants to "auto follow transforms"
3)Set Parameters Preferences to "show hidden properties"

Now you can move those pants independently of the girl and use translate, rotate, and scale morphs of each part of those pants.

4)Use the hip area when you want to move/rotate the whole pants and want to keep everything else. Reduce the y scale of the pelvis, and the thigh bend and thy thigh twist.

5)Play around with the other morphs of the pants to get the pants in approximately the shape and position you want.

Smoothing and collision modifier can help with finishing touches, but is a bit tricky as it can cause the pants to wrap around other parts of the body. It takes a bit of experience and sometimes a few more tricks.

6)The mesh grabber addon can also come in handy, but I can usually manage without it.

Very nice as always you and a guy named DENSOSARD (on other image boards) are really good at this keep up the awesomeness!

Densosard produces some great pee pictures. I'd say perfect.

The only thing that thing that keeps me from fully enjoying his work is scat content, which I dislike and which is present in quite a lot of his series.

Why not draw them peeing through the fly?

1)Few pants for girls for Daz studio have a working fly.
2) Pretty unnatural way for a girl to pee, unless she's using some sort of urination device. Girls who pee standing up usually pull down their pants.

Many thanks for your very helpful words !!

I will see if I can make some presentable images, and show them here.
This is an old one from when I was discovering DAZ, playing with some functions.

I'm always happy to see renders of girls peeing done by someone else. The easier option is to start with girls wearing shorts, because long pants are more difficult to adjust in pee scenes.