Curious about the phrase "しまいと" in a book I'm reading


I'm re-reading/translating a section of 金原ひとみ's 星へ落ちる for a translation course
I'm taking and ran into the following sentence:

> 彼がこの家にいない時、私は彼があの人と食事しているところとあの人とセックスしているところを想像 **しまいと**
> 、延々タバコを吸っては自分を無意味なものへ変えていく。

I've never run into this usage of しまい before and am curious about why it's
being used here. A quick web search brings up mostly the phrase 「しようとしまいと」, so
I've parsed it in this sentence as the equivalent of 「しない」, meaning that it's
the -まい form of する and making the sentence read as something along the lines
of "When he isn't home, if I don't imagine him sharing a meal or having sex
with that person, I endlessly smoke cigarettes and drift into a meaningless
existence."

So I guess my questions are:

  1. Did I parse this sentence correctly?
  2. Is there any particular reason for this usage of -まい? The novel consists mostly of a woman's inner dialogue and isn't at all formal, so this felt a little out of place.




You can forget the (よ)うと～まいと～ pattern described
[here](http://www.jgram.org/pages/viewOne.php?tagE=\(yo\)uto~mai%2C%20\(yo\)uga~mai)
for now. This まい simply expresses a negative volition ("I will not ～" or "I
will try not to ～") described
[here](http://www.jgram.org/pages/viewOne.php?tagE=mai-1), followed by the
quotative particle と. The sentence says "I try not to imagine the scene where
he ..." You can rephrase it as 想像しないようにしようと(思って), although it's a bit long.
The rule for using まい is found
[here](http://www.guidetojapanese.org/adv_volitional.html) (I don't know if we
can call this "mai-form").

This まい is indeed literary (as opposed to colloquial), and tends to appear in
written documents. But I feel it's not particularly formal. I haven't read
this novel, but in a typical novel, there is nothing unnatural when you see まい
in descriptive texts.




You can forget the (よ)うと～まいと～ pattern described
[here](http://www.jgram.org/pages/viewOne.php?tagE=\(yo\)uto~mai%2C%20\(yo\)uga~mai)
for now. This まい simply expresses a negative volition ("I will not ～" or "I
will try not to ～") described
[here](http://www.jgram.org/pages/viewOne.php?tagE=mai-1), followed by the
quotative particle と. The sentence says "I try not to imagine the scene where
he ..." You can rephrase it as 想像しないようにしようと(思って), although it's a bit long.
The rule for using まい is found
[here](http://www.guidetojapanese.org/adv_volitional.html) (I don't know if we
can call this "mai-form").

This まい is indeed literary (as opposed to colloquial), and tends to appear in
written documents. But I feel it's not particularly formal. I haven't read
this novel, but in a typical novel, there is nothing unnatural when you see まい
in descriptive texts.

