Did anyone notice that when Tyrion was giving his speech to Cersei, he mentioned her baby - surely at that point Euron needs to question how Tyrion knows she's pregnant?!
Also, I don't get Sansa's hate for Daenerys... she's sacrificed most of her forces to help the north but Sansa hates her.
Euron must have caught that. We didn't get to see him when Tyrion was talking about it but surely that was deliberate so to not make it too obvious that he put two and two together?