The title is clearly a tongue-in-cheek dig at the idea of masculine abuse. Instead of calling the vices in their home by their name, instead of accepting responsibility for himself, the father allows himself off the hook. Indeed, he plays the victim, and when he crosses lines, the titular saying comes to mind. Is he just being One of the Boys? The value of such a question is that it brings this extreme instance of abuse into a metaphorical lens—the story represents something more broad than its plot.
Perhaps the implication is simply that there is a way that masculinity harms children when it is used as a tool in the home. The idea of using a construct as a tool is complicated, but effective, especially against a child, because they will trust the ideas they are taught. The child is positioned in a kind of innocence that stands in sharp contrast with the father's deliberate evil and self-centeredness, but notice that by the end, the young narrator has adopted his father's vices.
The portrait shows that these are cyclical problems, and the implication from the plot is that the unnamed narrator will have to break the cycle of abuse and addiction (unnamed as a way of suggesting universality, perhaps?). The question is about victimhood, because, although the narrator is quite literally a victim, he also indulges the same vices that led his own father to abuse him in the first place.
