Nipple stimulation leads to urinating

It's the male version of squirting. Fairly common for this to happen to women, but extremely uncommon for men. If I understand it correctly, for men there's something inside the urethra that closes when we get close to ejaculation that prevents urine to exit the bladder. The absolute majority of men only ever orgasm while ejaculating which makes squirting impossible. Since you're stimulating the nipples instead of the penis, you're not building towards ejaculation and that thing inside the urethra remains open. Once you start to gain high levels of arousal, the bladder starts to fill up and you may start to leak urine.

Ah, crap 🙁 !!!

I dont like that. I used to be able to have a traditional ejaculation by only nipple stimulation but the orgasm was so much more intense. Sometimes I had dry orgasm and extremly powerful dry orgasms.
Now instead it hurts like hell cause my bladder fills up so much that it feels its gonna burst and its painful. First it feels good and then, BAM! Pain, and with in 10 minutes! I dont think thats normal.

I dont want to squirt haha. So my body have changed somehow.

Might be your body adjusting to a new type of stimulation. When I first started a Kegal regime I would get the urge to urinate when I released the clench of the Kegal; that sensation vanished after a month or 2 of Kegaling. There were also several times when I urinated some while using my Aneros; that has not happened in more than a year.

i always have the feeling of wanna urinate when I am riding p-wave while relaxing my muscle. so far i did not really have one, it just the sensation altho i might have a few drop and i do not care

Yup, been there.... etc. Remember that most of us spread one or more towels on our bed before a session. Our wives and GFs have a tougher time of this than we do since their nips are more strongly wired to their uterus -- so that suckling of a nipple by a newborn works to contract their womb and along with that the smooth muscles in the bladder also contract. Aging is also a factor for both women and men but we guys aren't well trained and developed to control the 'drips' and 'drabs' which accompany bladder contractions. You might consider chatting with a wife or g.f. who has been through post child-birth training. Get her thoughts about your "problem."

A complaint to your Pricare Doctor or Urologist can yield some tests that will reassure you that your kidneys are OK and the hormones that direct urine production are within a healthy range.

That done, you have some choices:
1. Read through some web posts on sports hydration, urine production and how fluids like coffee, tea and sports drinks affect your kidney output. I used to put a liter of Gatorade on my night stand for any kind of session that was going to excite my innards. The last few years I've taken a look at how Sodium, Magnesium, Potassium and the other major electrolytes affect my urine load and sooth or irritate my bladder. Ask your Doc or Trainer for help in modifying the composition of your hydration fluid. Practice sound hydration particularly during long sessions. Having to end a session with a muscle cramp or spasm is no fun at all. Try some stretching exercises before your session.

2. Once you get your urine production and bladder stress coraled and your bedding covered it may be time to consider what few men wish to do. Wear a brief (or thong) and put a Shield or Guard in there. This won't stop a flood from a full bladder but it should help you through a tight spot and let you improve your ability to stay mindful, relax and enjoy those intense orgasms.