The venue’s policy on groups in fancy dress or out for their bachelor parties is intended to combat any disorderly antics that might occur as a result. And at face value, it’s a fair rule; after all, no landlord wants their pub destroyed. But this wasn’t exactly the most volatile group going.
And, perhaps unsurprisingly, the priests-in-training first assumed that the doorman was joking. He was deadly serious, however. So they attempted to argue back, insisting that they really were students of the church. Unfortunately, though, the doorman didn’t believe them and so told them to leave.