A mug would be gullible person or someone just stupid, you stupid mug. We also have the expression to mug someone off - don't do it in front of your friends. Ireni is sarcasm and Jammy means lucky. Knocers mean breasts or boobs or tits. Leg it, meaning run away. The lurgy, lovely, jubbly was from that TV show. Only fools and horses. Mental, absolutely mental. Crazy. Oh, those peanuts are really Moorish... Are you mugging me off? There you go, folks.