I feel like Araki is bad news.

Think so too

Why else would the author put some random slut in here

And the way his eyes looked at this page ...
http://www.mangago.zone/read-manga/fushidara_na_hanatsumi_otoko/mi/099e3966120641c6472c6cb93c8b6403_chapter-18/11/
..looks like he was planning something really nasty. Like for example "to break up happy couples"