Question for Married men

My friends and I often have discussions about polygamy, human nature & differences between a man and a woman’s approach to relationships etc and we often come to the conclusion that men by nature Can not be Monogamous. Do you guys agree? my question is for married men in happy relationships who madly love their wives. Do you guys still fantasise about other women? If you see a beautiful woman at the mall or walking down the road do you guys feel anything towards them? Or ever daydream about an old love interest? Nothing emotional just plain physical attraction? Do you guys consider it a minor form of cheating or not? And do you think men can love multiple women at one time?