Not my thing but I'll explain.
This is StableDiffusion 1.7.0 and VirileReality 2.0 (not XL or BETA 3) with a style filter called Cinematic. This filter goes like this:
"cinematic shot, dynamic lighting, 75mm, Technicolor, Panavision, cinemascope, sharp focus, fine details, 8k, HDR, realism, realistic, key visual, film still, superb cinematic color grading, depth of field, natural beauty".
Regarding piss, this detail took quite a number of tries using the InPainting function (img2img) to rework the original shot with prompts like "water, shiny jet, spouting water, water drops, etc.". Definitely not working with simple "piss", "piss from penis" or suchlike. And forget about "yellow"... (dear me, what am I writing!)
Much depends on the existing background and lighting - hence my mentioning the style filter - it worked well here because it's darkish/brownish/shadowy and there was a pool of water on the ground. Much harder with a clear, sunny background, I guess. You must also try to make the jet as thin as possible and use irregular, separate sections.
Still you might search CIVITAI for something simpler.
Hope this helps!
