These days it is not unrealistic for the father to care for the children as well as the mother. Single parent homes are becoming more common, and the father may be obligated to care for the children himself. The only thing that is not expected of men is to nurse the infants by breast feeding after birth. For awhile this reason was merely because society did not believe that men were capable to lactate. In the article “Father’s Milk” in which I am referencing the author talks about why they believe human males are capable and why they may not be.
The article explains how there are only one or two mammals where the males lactate naturally one of these are the Dayak Fruit Bat. Now there are technologies such as hormone injections that have been shown to cause lactation in males and virgin cows. The steers have been injected with estrogen and progesterone and began to produce milk. Cancer patients that were treated with estrogen supplements started to secret milk as well as individual injected with Prolactin.
The only concern the author had with men beginning to lactate and care for young was the lack of experience that they actually have. Women have been taking care for their young for so long that they have become natural nurtures. It would be difficult for both parents to be tied down unless it could be done equally. In most cases with other species the male gathers food while the mother nurses the young if the male had to nurse the young as well it may delay hunting or going to a job in humans.
Here is the link to the article