I'm just gonna throw out there that my take on this chapter is not to have Yuuma set off red flags, but instead to paint a picture that just like in Meguro's case, not all people who have had lots of sex are bad people. Since many other series would probably paint him as an insensitive playboy, I'd like to think that the author is instead trying to do the opposite. So yeah, basically the manga seems to be rather sex positive for him as well, not just Meguro. Or I'm totally wrong, but I hope I'm correct because this manga has been really cute so far.