Missing a Mean Gene

I've decided that I am missing an important gene that would help me with snappy comebacks after someone says something unkind to me. I am missing the useful mean gene. Here are some ways that having a mean gene would help me out:

When an acquaintance (who is an unhappy divorcee estranged from her children) is going on and on about how much money she makes compared to me, I could say "I don't make a lot of money, but I have rewarding relationships and pleasant evenings with loved ones." That might shut the bitter bitch up.

When a coworker pointedly comments on my weight gain and her weight loss, I could say, "At least I have an ass, Olive Oyl." instead of half apologizing by saying something mild and like "Oh, curvaceous is in these days, so I am trying it out." WHERE IS MY SPINE?

Given how I feel about people with a dominant mean gene I should be glad not to have one, but still, it would come in handy sometimes.