Nameless
Member
It wasn't the cup. Because IIRC was Joffrey was the only one eating the cake?
And there was the dead pigeon inside the cake as well.
He puts the cup down when slicing the pie. The second time he drinks from it is what does him in.
I don't know, but I get the impression from the poison that it's the type that works instantly and violently. As soon as he drinks again he starts dying.