Rather Disorganized attachment style. Sounds like he has a desire for closeness, is prone to regrets and shows behavior symptomatic of both anxious and avoidant attachment style
For men it's the most effective way to spread your genes, a very strong evolutionary driver of behavior.
They call it the seven year itch, but it's more like the four year itch, statistically. Stick around long enough to get children to a point where they're somewhat self sufficient, then look for another chance to mate.