From "I, Claudius: Reign of Terror (#1.8)"
[of killing Sejanus's children
I can't do it. I can't just kill them, they're underage.
They're on the list. Now get on with it.
The girl is a virgin. It's unprecedented to kill a virgin. It will bring bad luck to the city.
Then make sure she's not a virgin when you kill her. Now *get on with it*.