Well...Getting your balls examined and getting an erection if it's a hot female doctor, I'm sure anyone would react that way.
Still, a request to get a mold of your shape, huh? Kind of a side benefit that takes your mind off the...operation, doesn't it.
Infertility,though? Probably one of the worst fates to befall a Hentai Protagonist...
Infertility shouldn't be that of a bad fate for a hentai protagonist as he can pretty much go in raw every time without the fear of a pregnancy sequel...
Impotence on the other hand...
Later on she realizes that (despite the fact that the dildo became a bestseller) having tasted his dick in it's full glory she can't be satisfied with a mere replica... Or he realizes that the whole mold story was a lie and that she is in fact his stalker...