It appears that President Trump is not going to let go of Mayor Pete Buttigieg’s Fox News town hall anytime soon.

After lashing out on Twitter that the right-leaning network is covering Democrats too much by hosting the Democratic presidential candidate (while also taking swipes at Fox News anchor Chris Wallace), the president took time out during his Monday night campaign rally in Pennsylvania to air more grievances.

Claiming that he watched “Alfred E. Neuman” on Sunday night—his Mad magazine nickname for the South Bend mayor—Trump then asked the audience: “What’s going on with Fox, by the way?”

“They’re putting more Democrats on than Republicans,” he continued, prompting the MAGA crowd to boo Fox News. “Something strange is going on at Fox, folks! Something very strange!”

As audience members tossed out more jeers at Fox, the president talked about tuning in to the Buttigieg town hall, asserting that he needs to “watch the competition—if you call it that.”

Trump, however, still seemed rather peeved that Fox News provided airtime to a Democrat.

“He was knocking the hell out of Fox,” he said, referencing Buttigieg’s criticism of Fox News hosts Laura Ingraham and Tucker Carlson. “Someone’s going to have to explain the whole Fox deal to me.”

In recent weeks, the president has been fairly critical of his longtime favorite cable news network, even while he continues to give them the vast majority of his television interviews and live-tweets their programming.

Besides his recent critical comments related to the Buttigieg forum, Trump slammed Fox News senior judicial analyst Judge Andrew Napolitano—who has said the president obstructed justice—while claiming he turned down Napolitano’s request for a Supreme Court spot. He also whined when Fox brought on Democratic presidential hopeful Bernie Sanders for a town hall, criticizing moderator Bret Baier for being “so smiley and nice” and accusing the network of banning his supporters from the event.