If you're getting numbness you're doing it wrong. Try standing every few minutes, and especially if you feel numb, adjust the tilt of your saddle (up or down) or try different saddles. I only ride 50 miles a week as a commuter, but sometimes I will ride up to 50 weekend miles, such as in the annual Ride for Heart, and I have never had numbness (or sexual dysfunction) related to cycling.
Seeing your doctor is never bad advice, but at the same time, they may know nothing about bike related issues. A good bike fitting can help too.
As for the medical site you quoted, in fact you should have most of your weight on the ischial tubersosities, as well as partially carried by your feet and hands, so that very little pressure is on the perineum.
There's also the possibility that your wife is mistaken and maybe isn't keen on you biking which has made her overly attentive to this issue. However, since you are reporting numbness lasting 45 minutes after you finish riding, she may be on to something.
Last edited by cooker; 05-11-09 at 10:08 AM.