President Donald Trump finally lashed out at his niece and author of the best-selling book Too Much and Never Enough Mary Trump on on Friday evening with a series of tweets that accused her both of writing “untruthful” things about him and his parents and violating a nondisclosure agreement she reportedly signed with the family.

“I am the ultimate member of The Book of the Month Club,” Trump tweeted. After blasting “lowlife dummy” and “war mongering fool” John Bolton, who published his own White House memoir last month, the president moved on to his brother’s daughter.

“Next up is Mary Trump, a seldom seen niece who knows little about me, says untruthful things about my wonderful parents (who couldn’t stand her!) and me, and violated her NDA,” he wrote of the two-way agreement that he is now also apparently violating. “She also broke the Law by giving out my Tax Returns. She’s a mess! Many books have been written about me, some good, some bad. Both happily and sadly, there will be more to come!”

A short time later, Mary Trump responded on Twitter by pointing out the fact that her interview with Rachel Maddow on MSNBC Thursday night got higher ratings than the president’s town hall with Sean Hannity on Fox News.