Brand, 35, married the 26-year-old US singer in October and it is claimed he is involved in the designing process of some of her wacky gowns.
A source said to UK newspaper Daily Star: 'Russell is very hands-on with all Katy's dresses and loves giving his opinions. He always tells her to show off what God has given her.'
Perry reportedly believes her long-haired lover is the perfect man for the job and he has been enjoying helping out with her work.
The source added: 'Russell now gets really involved with what Katy wears. He gets a buzz helping with those decisions.'