I've heard that it is not uncommon for men to get erections during or after battle due to adrenaline and increase in blood pressure. I can imagine that this might be very uncomfortable in a full suit of armor. Maybe these enlarged cad pieces were an attempt to address that.
You fight a dragon and get to the gorgeous princess that you risked your life for, the love of your life, you still got that armor on, you are going full mast, the fool is the one without armor to support it as they never truly believed they would defeat the dragon in the first place.