Una made valid points. it’s likely his ex was texting about his son (what else? They’ve been divorced for awhile.) But the thing is this behavior is not new and unusual one time thing. That’s how he typically behaves. Plus why does she need to ask? He could volunteer the info that he needs to discuss his son or something else happening.

I think he showed repeatedly through words and actions that he wants to keep it light and casual. He might be a cool guy but not relationship material in many aspects including no stability. Somebody who wants serious relationships wouldn’t live his life style. Not at his age. Plus he verbatim told you he doesn’t want commitment. How much more direct could one be? He said it for a reason. He has no intentions to string anyone along.

I see no point in pursuing him.