The reality is mammals have instincts that make sex pleasurable both both parties, and it is usually shockingly aggressive, even violent seeming. If people could get out of their head and into their body and primal desires- and quite literally act more like an animal, they'd have much better sex.
Chimps and bonobos, our nearest cousins, do have a pretty spectacular sexual toolbox of course that acts as a kind of social lubricant. But it's not all about reproduction, or even pleasure, and quite a lot of what they get up to will get you jailed in most countries.
Counter-intuitively, getting into this headspace makes sex last much longer, not shorter- I suspect human bodies and minds are different from a lot of other mammals in this regard. It is more often that anxiety, tension, and over intellectualizing causes issues with men not lasting long enough.
One glance at the animal kingdom - there are plenty of natural practices that will put you in prison for life.
Note: true, teenagers! I completely forgot =/