In The Stranger, we have the following passage.
So we took our time getting back, him telling me how glad he was that he'd been able to give the woman what she deserved.
I understand the meaning, obviously, but have trouble understanding the grammatical structure here.
"So we took our time getting back" seems an independent clause. So "him telling me how glad he was that he'd been able to give the woman what she deserved," would, logically, be dependent on the first clause.
Why is "him telling" is used rather than breaking the sentence into two and simply writing "he said" or "he told"?
I can hear how "him telling" makes most sense, but can't figure out how to fit it into formal grammar.