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.
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."