3rd Hatchling still "hatching"

13:22 pm: The male Blue Tit entered the nesting box and fed one of the two hatchlings. He then noticed the hole in the 3rd egg and inspected it carefully. He remained in the nest and observed the hatchlings until the female returned at which point he left to get a worm. The hole in the 3rd egg is now larger. It has been at least 2 hours now. With the last hatchlings it took at least 3 hours before it had freed itself from the egg shell. The hatchlings can be heard: a tiny high pitched chirping. The male again entered the nest after the female left. I wonder if this is his first batch of hatchlings. He seems to be a bit unexperienced and he takes enormous care at making sure that his feet are outside of the inner nest where the hatchlings are. The difference in behaviour between the male and female is significant. Fascinating!!