That’s really funny. I love this show. The suit he’s wearing is a Black Fleece, you can tell by the signature 3 button jacket and the ‘locker’ loop on the back of the collar.
I do have to take issue with the misconception of some commenters that this is how Thom Browne suits are supposed to fit, a misconception perpetuated by people who buy things at sample sales whether they fit properly or not. In fact a Thom Browne suit should fit very similar to a Don Drapper suit, the jacket is cut more square, so it doesn’t cling to the waist as Italian-cut jackets do and the pants are high waisted and with a straight leg, which means you can actually move in them. I would argue that brands like Prada and Jil Sander are made to fit much tighter than TB. The last time I bought a TB suit, at the TB store, I had to argue with the salesman to let me shorten the sleeves and the pants, I wanted to emulate the “Thom” look and he though Thom’s intention was for it to be worn in a more “traditional” way, we finally compromised at shortening it only by half and leaving enough extra fabric so it could be reversed to a traditional look if I changed my mind in the future.