I'm no Doctor, but good on biological Themes etc.
(and have had enough Sex to forget how often)
I had that Problem when i was younger... to easy to stimulate etc.
3 Things you can try (some got mention before):
- Train your Lower Body and Masturbate to the point of No Return then stop yourself from comming. There are a bunch of musles for a hard one and even more to control that whole monster XD. breathing does the job too (you can try to control your heartbeat too, less heartbeat less blood, less pressure on you).
-Try using slight numbing potions/lotions on it. Google it, but read what you buy and dont over do it.
-Mindtraining, simply try to thing of the worst possible woman you want to see naked and watch your favorite porn/ play with yourself/ play togehter on 69. Without getting a hard one in 1 sek und comming after 1minute.
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Too the can it damage things?
JES! Too much action after you spurt it into her can damage you a bit.
-Ejaculation Shaft Muscels aren't ment to be a Machine Gun.
-You'r blood circulation system can get damage too, too much pressure on the fine ends.
-Sperm that gets pressed back into... can be fatal xD... joking on that xD.
You should cooldown for atleats 5 minutes and start again when you don't feel any pain. Pain means last stop Signal from your Body... like when you put your hand on an hot metal surface.. without pain you would burn you'r Hand to ashes.