After both the message window and his buddy warned him of red flags his gf is hiding, he's finally starting to get it, calling her the "last boss".
Assuming she really is the dangerous landmine girl that she looks to be, I'm just surprised she keeps putting up with him when she secretly thinks he's a good-for-nothing. If I had to guess, maybe his good looks are real, and that he's just her meek trophy bf who's the "safe backup" while she has fun sleeping around with cooler looking fuckboys and loaded old salarymen. So he's there for her to show off to other girls that "she's taken with a hot guy instead of being a single loser with no bf like these other bitches are".
Whether it's true or not, next chapter should be interesting.