Here are 2 possible structures of the same sentence (including extra sentence for context).
Seriously, what is up with this unnatural behavior of hers?! She started acting like this ever since that stupid ring got involved…
And
Seriously, what is up with this unnatural behavior of hers?! Ever since that stupid ring got involved, she started acting like this…
From the novel PoV, which of them reads more easily and natural?
And what should I keep in mind, if I deal with such structure dilemmas in the future?
Please migrate the question if this is a wrong section for questions like this.