The German supermodel - who raises four children with husband Seal - insists she and the singer don`t need to wear "costumes" because their bedroom antics are already exciting enough, but she hasn`t ruled out dressing up in future.
She told America`s Cosmopolitan magazine: "I`m not big on costumes in bed, to be honest. I wouldn`t say no if he wanted to try, but it seems so inorganic. Maybe it`ll come later - in five or 10 years, I`ll start buying funny outfits. But for now, we`re nice and spicy in that department."
Heidi also spoke about her struggle to make it in the modelling industry, but admitted she was determined not to return to Germany from the US as a failure.
She added: "I could not get a job to save my life. I was in a sh**ty apartment, I didn`t know anybody, and my English was terrible.
"But it was my last stop, so I thought if I just try harder - if I just stick around a little longer. I didn`t want to go home having failed."
Heidi, 36, recently admitted she is so comfortable with her body, she is happy to be naked in front of people.
She explained: "I think it`s because I grew up in a very easy-going family where my parents were always naked.
"My parents are still naked. I mean, it`s not like we`re hippies and we run around naked, but if they happened to be in their room changing or something or someone comes out of the shower, they`re not, like, `Oh my God. No. Close the door.` "