I am unsure how to punctuate dialogue when it is interrupted by the thought of another character. So the omniscient narrator is the one doing the interruption here on behalf of the MC "Divorce actually. Though I'm from here originally”—No shit, thought Frank, hearing her accent—“but got whisked away five years back by a lad.”
"Divorce actually. Though I'm from here originally—” No shit, thought Frank, hearing her accent— “but got whisked away five years back by a lad.” I'm not sure it's considered correct, but it's how I do it.
Can't be certain about that second comma, nor do I have an opinion about the 'no', but I really think there needs to be a comma after 'Divorce'. The word 'actually' is used as an...interjection? The part of speech escapes me, but it's the one that needs to be surrounded by commas.
I would write it like this, but I think it all depends on the effect you want: "Divorce actually. Though I'm from here originally—” No shit, thought Frank, hearing her accent. “—but got whisked away five years back by a lad.”
Jmh is right about something--that's certainly a way to do it. I've seen it done both ways, split and non-split.
I would write it split, as @jmh105 did, because had the thought been said aloud instead of thought, each character would have their own line to make it clear for the reader to know who is speaking. In this case, the reader needs clarity on who is thinking as well.
It's a style issue, so it depends on your bible. I'm a practicing Chicagoan. From Chicago Manual 17 (6.87) Em dashes for sudden breaks or interruptions. If the break belongs to the surrounding sentence rather than to the quoted material, the em dashes must appear outside the quotation marks. "Someday he's going to hit one of those long shots and"—his voice turned huffy—"I won't be there to see it." I got the spacing right on those too, which is basically no spacing. Seems kind of strange with everything tucked in like that, but that's how they did it.
I agree in the example you used, and use it fairly often myself. But in the OP's example, another character's thoughts are interrupting. So wouldn't that be different?
Still fretting over this. How does this look, as an alternative? I have included a bit either side. "So Megan, what brings you to this part of the world?" he asked, dismissing his moment of concern about the picture as silly. Odds of anyone seeing that must be a million to one. "Divorce actually, though I'm from here originally.” She paused to allow a flicker of sadness to pass across her pretty face. No shit, thought Frank, hearing her accent. “But then I got whisked by this handsome lad, ooh, about five years ago now," she added, then raised her glass saying, "Here's to freedom," drained it and unleashed a smile that crinkled her grey-blue eyes. Frank nodded and smiled back, liking her now, imagining her little body against his.
I felt this alternative version was more awkward than the first. It splits the thought too much and it's kind of jarring (at least it was to me) when it goes back to Frank thinking about her accent. It's almost like he's reacting to the flicker of sadness and not what she said. But maybe others read it differently?
Maybe... "So Megan, what brings you to this part of the world?" he asked, dismissing his moment of concern about the picture as silly. Odds of anyone seeing that must be a million to one. "Divorce, actually, though I'm from here originally.” No shit, thought Frank[, or upon] hearing her accent, as she paused to allow a flicker of sadness to pass across her pretty face. “But then I got whisked by this handsome lad, ooh, about five years ago now," she added, then raised her glass saying, "Here's to freedom," drained it and unleashed a smile that crinkled her grey-blue eyes. Frank nodded and smiled back, liking her now, imagining her little body against his.
Interesting, "So Megan, what brings you to this part of the world?" he asked, dismissing his moment of concern about the picture as silly. Odds of anyone seeing that must be a million to one. "Divorce, actually, though I'm from here originally.” No shit, thought Frank noticing her accent. She paused to allow a flicker of sadness to pass across her pretty face. “But then I got whisked by this handsome lad, ooh, about five years ago now," she added, then raised her glass saying, "Here's to freedom," drained it and unleashed a smile that crinkled her grey-blue eyes. Frank nodded and smiled back, liking her now, imagining her little body against his.
That needs something. It doesn't look right, although that sort of isn't quite my bag. Try one of those two, though. Second, the 'she paused' part slows the conversation down a little too much, I think (again, YMMV, not my specialty). Try mixing it with the first sentence of the last bit. I'm a bit pressed for time at the moment, but I can work on it when I get back if no one's responded.
Well, this sounds like a good time to use italics for thoughts! At least, I expect that's how I'd do it. Closer third, less filtering, and more direct thoughts. No one was going to see the picture--he might as well chat."So Megan, what brings you to this part of the world?" "Divorce, actually, though I'm from here originally.” No shit, with an accent like that. A flicker of sadness passed across her pretty face. “But then I got whisked by this handsome lad, ooh, about five years ago now." She raised her glass and said,"Here's to freedom," then drained the liquor and unleashed a smile that crinkled her grey-blue eyes. Frank nodded and smiled back. He liked her now, and could imagine her lithe body against his.