Jessica Simpson's manager father Joe has given his personal approval to his daughter's romance with John Mayer, insisting he is a "big fan" of the Grammy-winning star. The Irresistible singer began dating Mayer in 2006, following her divorce from husband Nick Lachey - formerly of boyband 98 Degrees - which was finalised in June (06). And Joe Simpson is glad his eldest daughter has found happiness with Mayer, because now the couple are both famous in their own right, there won't be any career rivalry between the two. He says, "If Jessica is in love, I love the things she is in love with. I want her to be happy. I'm always a fan of (Mayer's). I love him; he's got great music. "I think the beautiful thing is that (he and Jessica) don't do the same thing. He's a legend already. There is no competition. He's a guitarist, that's his thing. Jessica is a singer. She doesn't play guitar, so there's no competition."