Donald Trump supporters were left aghast — shocked! — last week when Professor Pamela Karlan had the nerve to crack wise about the president’s young son, Barron, during the impeachment hearing in Washington D.C.

After all, he’s just a kid.

Melania Trump, who created the #BeBest anti-bullying campaign, was quick to scold her for such a clear transgression.

“A minor child deserves privacy and should be kept out of politics,” she tweeted. “Pamela Karlan, you should be ashamed of your very angry and obviously biased public pandering, and using a child to do it.”

The first lady makes a good point, and perhaps her husband should listen to her, considering just days later he called out a minor child in what some might also describe as “obviously biased public pandering.”

Here’s the president’s latest jab at 16-year-old Greta Thunberg, which he tweeted out after she was named Time’s “Person of the Year”:

Trump’s older son didn’t like it either:

As older folks should know by now, it probably isn’t too wise to tangle on social media with teenagers who grew up with iPhones AAPL, +3.75% glued to their hands. In this case, Thunberg scored a nice counterattack by using the president’s tweet to update her Twitter TWTR, +1.62% bio:

Is Trump, who took the title in 2016, feeling a bit slighted? After all, he was one of the finalists this year, and he’s shown huge interest in the award before. When asked who should win the 2018 honor, he reportedly said, “I can’t imagine anybody else other than Trump, can you imagine anybody else other than Trump?”

Either way, this isn’t the first time Trump has hit Thunberg on Twitter.

She struck back on that one as well, changing her Twitter bio at the time to: “A very young happy girl looking forward to a bright and wonderful future.”

Come on...be best, you guys.