The Infamous Yaoi P-List 1 (WARNING: Hardcore kink ahead!)

Recommended (even for those who don't like bara)
Omorashi- wetting underwear, peeing during sex (uke), urolagnia
Bara
My Reading Manga website

A magazine reporter and a pro-bicyclist both discover a kink for being stimulated and coming while still wearing their underwear. During a hot sex session, the uke (reporter) becomes so aroused, he begins peeing in his underwear.

Recommended
Ch. 13.6 - Peeing during sex (seme- in uke's ass), urolagnia

During a very intense sex scene, the seme becomes over-stimulated, loses control and pees inside of uke.

★ Special thanks to Manga Love for the recommendation

Recommended
Ch. 7 Urethral insertion/stimulation

Seme uses cotton swab to stimulate the uke's urethra.

Ch. 11.5 - Urolagnia

Seme asks uke if he can watch him pee. Uke refuses.

Vol. 4 extra 1 - Omorashi- naked wetting

Seme imagines a "urination anniversary" with the uke peeing himself.

Ch. 14.1 - Rosy palm technique

Seme overstimulates uke, causing him to pee. Later, an ill seme asks the uke to hold his urinal bottle while he pees in it.

Omorashi- wetting underwear

The couple from "Punch Up" are back. This time, seme sneaks into a closet to catch a man he suspects of targeting his uke. When he jumps out, he scares the guy so badly that he wets his underwear and faints. The seme admits he's impressed that the man could piss with a full hard on.

★ Special thanks to TooDeepInThisShit for the recommendation

Recommended
Ch. 5 - Desperation, peeing during sex act (uke- on seme's face), golden showers

Amami suddenly has the urge to pee while receiving oral sex. Hacchi ignores his frantic requests to go to the toilet and instead purposely intensifies his efforts. Amami loses control and pees in his mouth and all over his face. Hacchi doesn't seem to mind one bit.

★ Special thanks to TooDeepInThisShit for the recommendation

Peeing during sex (uke), urolagnia
My Reading Manga website

Chi-chan can't help peeing during sex, so Akehoshi puts a ban on that activity until Chi-chan cures his "bad habit". Later Chi-chan catches Akehoshi in the school shower and he decides to have sex since it's a safe place for pee to be leaked. Chi-chan mistakes this as "pee as much as you want", so he happily lets loose.

★ Special thanks to Sayrrin for the recommendation

Omorashi- naked peeing, rosy palm technique (variation- see summary)
Notable manga
This will take you to the website “MyReadingManga

A seme who wants to learn how the uke cleans himself after sex, overstimulates uke, causing him to "squirt".

Studies have concluded that male (and female) "squirting" is indeed a release of urine: https://drjengunter.wordpress.com/2015/01/10/squirting-during-sex-is-urine-new-study/

★ Special thanks to TooDeepInThisShit

Desperation, peeing during sex (uke), rosy palm technique
My Reading Manga website

Uke forgot to go to the bathroom before getting into a long sex session. Seme presses on the uke's bladder and uke announces he really needs to pee. Seme tells him to go ahead and let it out and overstimulates him by rubbing the tip of his penis vigorously. Uke pees on the bed and then cums right after.

Desperation, omorashi- naked wetting, peeing during sex act (uke- during handjob)
My Reading Manga website

Sorey is molested in the bathroom by an older man who wants to jerk him off. Sorey tells him he has to pee and the man tells him to just go. Sorey pees and comes at the same time.

Yes, this is possible... but it is *extremely* rare.

★ Special thanks to AnimeMangaYaoi69 for the recommendation

Bedwetting, desperation, omorashi- wetting with pants pulled down, peeing during sex (uke), urolagnia

Three one-shot stories-
1) Sousuke teases a desperate Rin who is trying to get to the bathroom. They have sex in the bathroom, with Rin peeing after cumming. Surprise ending.
2) Childhood flashback with Sousuke wetting the bed.
3) Rin confesses to peeing in the pool. Sousuke confesses to a pee fetish.

★ Special thanks to TooDeepInThisShit for the recommendation