Ok. Let's do this nice and slow for the Down's children in the thread.
1: Look for the clues in the thread. By reading the thread, you can notice that more than one post mentions the words "my friends mom".
2: Plug it into rapidsearch.http://rapidsearch.yi.org/?s=my+friends+mom
3: Look for likely downloads on that page!
The file has been posted on /a/ before
It looks like it's rape
It's a translated doujin
4: From this, we can eliminate the various files that Rapidsearch spat back at us until we are only left with one: