I anticipate some hate for suggesting this, but tangible benefits do exist: Yoga.
A big part of prolonging a sexual experience and delaying orgasm is breathing. Keeping your breathing slow, deep and regular will keep your heart rate down and let you last longer. In conjunction with good cardio, its possible to last very long. Try it next time you're getting down with someone, or give Yoga a shot as proper breathing is a core component of it and teaches the skill.
While Yoga may get you results - the fact of the matter is, it's not really the Yoga, but that it teaches you to regulate your breathing under strain. You can learn to do that without Yoga on your own - or you can just do it during sex - focus on the breathing while you are pumping away at her, and the result is clear on being able to last much longer.
Some people say doing weights helps a lot. I disagree with this general statement - and I think doing a lot of squats helps, nothing else. Testosterone boosts from squatting, the increased muscle mass and ability to withstand strain, and strengthening the core, all these things help tremendously in performance and sustainability during sex. Guys who go to the weight room and spend their time focusing on pecs and arms are not going to benefit their sexual performance from it.
Get rid of the belly fat and replace it with abdominal muscles. That helps in performance too.
And.... eat lots of fruit on the day of having sex. Not coffee, not meat, not potatoes, not really vegetables - eat fruit. Fruit wakes up your body and gives it the kind of energy you need for sex - light and potent.
As for making your dick bigger, I swear bbbj's are the answer. Just get the girl to keep sucking for a good long hour every day and you'll swear your dick has grown a couple inches permanently.
