The sentence
- I marveled that you chuckled that I said "juxtaposition".
suffers from "that" overload. We'd all agree.
It's easy to slim either 'that'. Hence either
- I marveled you chuckled that I said "juxtaposition".
- I marveled that you chuckled I said "juxtaposition".
sounds fine.
Does any rule prevent us from going all the way and discarding both?
- I marveled you chuckled I said "juxtaposition".