can not get villagers to mate

I have tried with 3 different couples and they are of age to mate
but it seems no one is mating. Has anyone else had this problem?

thank-you
Viola

After selecting the villagers I want to "go inside" (shooting for the natural talent I want the baby to have) I keep throwing them together multiple times before they ever reach the hut. This gives each more experience. Suddenly a babe is born! Hope congratulations will soon be in order! Good Luck - Jiggy