Night of the Nearly Dead - S3-E7
Corrected entry: In 'Night of the Nearly Dead', when Eoin's agent is talking to Ted at the end she says a lot of his behaviour is caused by his 'problem' and Ted replies 'Ah, yes, he mentioned that earlier', but Dougal was the only one who heard him talking about it.
Correction: Dougal is apocalyptically stupid. When told not to mention Bishop Brennan's son, it is the first thing he does - the same with Ted Seller's ridiculous toupee. Obviously he has told Ted about Eoin's 'problem'.