Thank you for your hard work!
"A prince who cannot sire an heir cannot inherit the throne."
…Someone here is clearly ignorant, because that's not how things work, especially not in the Western World. (Besides, given all his hanky-panky, the Second Prince (who's not a eunuch, by the way, since he hasn't been castrated; he's become sterile) probably has at least one illegitimate child, who could be legitimised if he marries the mother. So even if reproductive ability were required for inheritance — yet again, that'd be limited to Imperial China, or maybe the Far East, not Europe ever — whether he presently has the ability or not wouldn't even be relevant.)