Well, it depends. The breeding (parenting) skill is increased with each kiss, not with each child. The more "tries" it takes to produce a child, the more skill the villager gains. Also, a villager gains skill in an area only by initiating the activity. So, if your women are being "courted" by the male villagers, the men will get the skill (even though the mom is the one who cares for the child). That's just how it works.