Not pee related but here's a Somno Fantasy I've had recently.
So content warning for Somnophilia
I have him in a chastity cage for an entire month. Periodically taking it off to edge him a couple times a week. He's so horny he oozes with precum anytime I'm bottomless or even topless. He is just so desperate to cum.
One night I'm extremely tired and wanna go to bed. To test his resolve and planning something for tomorrow. I remove his cage for the night. It's a hot night so I go to sleep naked without a blanket. Getting wet from how desperate he is. I make him cuddle me and fall asleep to him whimpering. He puts his hand between my thighs and can feel how wet I am. Any time his dick grazes me it leaves a trail of precum. I finally fall asleep.
Later I half wake up to him humping desperately. Soft moans and him whispering apologies. He couldn't hold it anymore. I go back to sleep. And he repeatedly cums in me. He spends all night humping and cumming and filling me to the brim. Towards the end I'm just pretending to be asleep. Listening to him go. He eventually can't even cum anymore. He's just humping because of how good I feel.
And when I wake up that morning I climb on top of him telling him that I made him wait all night so we could have really good morning sex. And he's just laying there looking guilty and has to confess.
He failed his task of not cumming so I get to punish him. Probably gonna edge him for 3 months this time.