this is how you increase stamina, fix premature ejaculation.
you gotta to condition your cock, train it, like bodybuilding or any type of training.
when you jack off, pace yourself, go fast, go slow, when you're getting close to finish, release the cock, then start over.
THAT'S IT. repeat that cycle over and over, the longer you do this, the more conditioned it will be. I've done it up to 40 mins, probably even more lol. lasted much longer, also, caffeine helps, have an energy drink or 2 prior to sex. and ummm, pinch yourself real hard when ur about to cum (while ur fucking ur girl)
There you go fella, you just became a better man in bed, night and day difference