To be fair, I saw some people saying his geriatric diaper leaked and this is a suction wrinkle. I disagree.
There is no discoloration of the pants and the back of my suits get wrinkled there as well because it’s roughly where your hamstrings hit the edge of the chair.
And given that he had a severe case of COVID, his kidneys may not be fully recovered. So I don’t think the diaper is fair game.
If it’s not a diaper then maybe his pants were mistakenly tailored with two backs because of his enormous front butt.
For the QAnon fans: this is clearly Jerry Nadler disguised as Trump to make him look bad.

Trump will get old but schadenfreud never will.