The reality TV star - who is currently in the process of splitting from the blonde beauty - believes they are not compatible as a couple as he loves being in the spotlight and she wants to lead a "calmer" life.
He said: "We love each other but I`m a famew***e and I`ll never grow out of it. Heidi knows that and doesn-t want that.
"I want every kind of press. She believes in bad press. There`s no way my love for fame and her love for puppies will every work out successfully. She just wants to hike and hang out and be calmer.
"She thought I`d burn out of this, but no. I`m still the same Spencer who went on `The Hills` to be famous. I still need to do stunts and take cues from Brad Pitt and Tom Cruise."
The 26-year-old media personality also admitted he and Heidi had clashed constantly since they married in April 2009.
He told People magazine: "It`s been a constant battle since we got married. She would be like, `Are you really Tweeting that? Are you really doing that?` "
Despite being known for his confrontational ways, Spencer does enjoy quiet time and has taken up painting.
He said: "I`m an artist now. I have an easel and everything. I`m going for an art show and a gallery."