Yes it's bad, especially because the MC just takes it all...
You are a bad influence on others...sure, says the alcoholic and then theres Miller
Like don't you think the parents, guardians etc won't ask why he is back weeks earlier ?
And why should the MC agree to keep silent ? There is literally no reason for him to agree to that, especially if he is pissed and felt treated unfairly...be it to his parents, friends or even the other girls...you really should have the option to actually say 'no i won't keep silent, let's see what happens'.
Who do you think has to lose something here ? If the MC simply tells the truth, alcoholic teacher, other co teacher a gambling addict, took him into a stripclub/gambling den (run by a criminals), left him alone there etc...