@Bumblebee1980a
Can you define man-child? Do you mean someone who won't commit to one person long term? Or one that has the life of a teenager, or both?
Nothing to do with commitment. Behaving like a child, refusing adult responsibilities, like caring for the children he has helped produce, or the household he also lives in, or making the food he also eats, and who deals with none of the mental load, weekly, medium or longterm planning, and will only ever grudgingly agree to do 'jobs' (like looking after children, which he views as 'babysitting' or housework (viewed as 'helping you out') if specifically told to, like a reluctant teenager who really doesn't get why he should be contributing to family life, and then behaves as if he's done you a favour by doing them, often incompetently.
Strategic incompetence is also often key. I have a male friend who, despite being high-powered at work, can't cope with both his children at once, and who (when he got divorced and was having the children EOW by agreement) wanted his ex-wife to only send ONE of the two children on those weekends, so his wife never got a weekend to herself as she would always have one child at home, but he only got one child at a time to 'manage'. He also told her he wouldn't be doing his daughter's hair while she was with him, as it was 'too hard', and that she needed to send the children with pre-chosen outfits, packed together so he didn't need to figure out appropriate clothing. (Obviously she told him to cop himself on.)