Narcissistic supply is the attention, admiration, control, or emotional reaction a narcissistic person needs from others to regulate their self-esteem. Praise is supply — but so is your distress, because both prove impact. Understanding supply explains a lot: the charm offensive when you pull away, and the provocation when things get calm.
Admiration, envy, and applause are positive supply. Your tears, anger, and desperate explanations are negative supply — still proof of power. This is why staying calm and unreactive (gray rock) can reduce provocation: it cuts the payout.
When supply runs low, conflict is a reliable pump. Many partners notice fights that seem to come from nowhere right when things finally felt peaceful. It isn't random — peace is low-supply.