From the little that you told us about your boyfriend I gather that the best way would be to ask him outright for a proper explanation.
If he dithers or makes excuses, the decision will be yours to dump him, like I suggested before, and start afresh. He doesn't sound too reliable, seems to be liking his freedom and he won't change.
He has a child with an ex "partner".... Not an ex wife....
And other exes come around to spend the week-end with him...
What makes you think that he will settle down...???
Dump him at the first chance you get.
There is plenty of other fish in the sea....