It's always the little things

A person I work with is taking great delight in a grammatical mistake I made. I'm not sure why he's taking such delight in my mistake, but he's now pointed it out to 4 people.

I'm fallible. I'm not perfect. I'm the first to admit it. Though I made the mistake, it also slipped past the eyes of THREE OTHER SMART PEOPLE. It was proofed and accepted by all three of them.

And yet this person that I work with continues to chuckle and snort under his breath about MY MISTAKE.

It's a little lot annoying.