pour salt in(to) the/(someone's) wound(s)
To make something that is already difficult, unpleasant, or painful even worse; to accentuate, aggravate, or intensify a negative situation, emotion, or experience (for someone). After losing the championship match, it really poured salt in John's wound for his girlfriend break up with him the next day. My pride was already hurting when I didn't get the job, but hearing that they gave it to Dave really poured salt into the wound. I can't believe you would ask me to pay you back on the day that I got laid off. Thanks for pouring salt in my wounds, man.