Julie, as others have said, you deserve better. I know it's tough, but I hope you find the strength to walk away from this man. If you want a monogamous relationship, don't settle (or risk your health) for anything short of that.
And brains do not equate to emotional intelligence or integrity.
(((((())))).
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher