"I told him Katy would get upset if he acted like he didn't have an opinion on what flowers to put on the table. They don't want to hear 'It doesn't matter' - they want you to seem interested. But ultimately they want you to agree with them. Organising a wedding is stressful - you don't want to fall out with your future wife over something like the lettering you have on your invitations." British funnyman David Walliams on the wedding advice he gave pal Russell Brand, who married Katy Perry on Saturday (23Oct10).