Jada Pinkett Smith and Will Smith

Jada Pinkett Smith and Will Smith

Jada Pinkett Smith gets turned-on when Will Smith challenges her "spiritually and intellectually."

The 43-year-old 'Gotham' actress, who has son Jaden, 16, and daughter Willow, 14, with the former 'Fresh Prince of Bel Air' star, 46, admits she is very attracted to his brain.

She said: "I read a lot of spiritual and self-expansion books. Will and I were just reading 'The Tao of Physics' by Fritjof Capra together and having long discussions about it.

"It's a big turn-on for me in a relationship to be spiritually and intellectually challenged by Will. To me, it's like foreplay! Of course, I enjoy that I have sex in my relationship, but I think this other intellectual aspect is quite unique and something that strongly connects us."

Meanwhile, Jada claims she no longer pushes herself as hard as she used to in the gym because she is getting older.

She told Shape magazine: "My energy levels just aren't the same. My joints, my knees, the amount of weight that I can push versus what I did in my twenties, how long I'm willing to work out. For example, I'm not staying at the gym for two hours anymore. I hit it and quit it...I'm not going to stress my body that way anymore. I can't."