Never A Full Erection

"I found you when I was doing a search about masturbation and ED. I'm not really sure how to explain this all so I'm just going to tell you and hope it makes sense. Our quest started a couple of months ago when my son (now 16) walked in to the master bathroom and saw me. It had been six days and the usual shower chub turned into a full hard on. You know that final sigh of relief right after you come? That's the point I was at leaning against the wall with my eyes closed and my balls cupped and still sliding my other hand real slow along the shaft. When he spoke it scared the crap out of me only because I wasn't expecting it. It's not like he's never seen my dick but he's never seen it hard that I know of anyway and certainly not jerking off (though he has now). He asked why he couldn't do that.
Thinking he meant jerk off I told him that of course he could. He again said he couldn't. Couldn't come? No he meant his dick wouldn't get hard. I can't go into detail because I'm afraid of sounding too creepy but he proved his point. He produces pre-come and his dick chubs but there's never a full erection. How is this possible?"

This is not good. He's smack dab in the throes of puberty. He should be dealing with "perpetual boner syndrome" right now.

Due to age - if he's in good health and not overweight - the usual causes like vascular disease can most likely be ruled out, though a doctor will still want to run those tests. If all tests return within normal ranges, a urologist needs to do some more digging. The standard monitoring for nocturnal erections might be suggested, though embarrassing for him to even have the machine in his room. But, you can help him be discreet, right? You might ask a urologist to shorten the discovery period with an injection of Aprostadil (Caverject) into the base of the shaft, which should cause your son's cock to get hard.

If that doesn't cause him to develop an erection, my guess is he has a Venous leak. According to WebMD, the penis must store blood to form and keep an erection. If the veins can't keep blood there, you either won't get fully hard or, if you can, it won't stay hard. An ultrasound of his penis and perineum would discover such a leak.

The fix for that is Vascular Reconstructive Surgery, which you can read about HERE. In short, a vein is transferred from the stomach area into the penis. It's a fairly decent option for younger men who have ED caused by injury to the area. The bad news is, "Even the best studies show that only 1 out of 20 men improved after the treatment. The success rate is higher for younger men with a single damaged blood vessel from a pelvic or genital injury."

In your son's case, that last sentence is the good news. Regardless, it's important that you get to the bottom of this. He's missing out on a right of passage, and a time of learning about his body's sexual response.

So, hie thee to his doctor where you will most likely be the one to do the talking. You'll have to be in there for any exam, anyway.

Though, I dare say, after a few visits for tests your son should develop enough confidence to speak for himself - - as long as you don't stutter and stammer and turn red with embarrassment during the first exam.