It's not every day a member of Congress drops by a Twitch session.

Streamers of a session of Donkey Kong 64 on Sunday were treated to a cameo from newly elected Congresswoman Alexandria Ocasio-Cortez.

YouTube star Hbomberguy, a.k.a. Harry Brewis, is streaming a Twitch marathon of the classic 1999 Donkey Kong adventure platformer released by Rare for Nintendo 64, which he'd never finished as a kid (preach).

Brewis explained in a video announcement he intended to play the game start to finish, streaming from January 18 to raise money for Mermaids, a charity providing resources and support for transgender children and young people.

"I chose to support this charity because as a person living in Britain, I find the media discussion surrounding this issue in my country, especially in its tabloids, to be woefully misinformed," he said.

"I’d like to do my bit to help support the people who do the hard work of contributing to people’s thinking on an important issue."

But there's more to the stream than a nice thought. Brewis said he chose Mermaids specifically to "spite" comedy writer Graham Linehan, who worked on British sitcoms Father Ted, Black Books and The It Crowd.

Linehan recently made headlines after encouraging people to oppose a substantial grant given to Mermaids from the Big Lottery Fund — a fund which awards grants to UK organisations, accumulated from tickets sold to the National Lottery — reportedly saying the charity pushes an "extreme ideological agenda." As a result, the charity's awarded funding is under review.

"Well done, Graham," said Brewis in his video. "Now, tons of people know about Mermaids, and support them just to spite you."

As of the stream's 52-hour mark, Brewis had raised over $270,000 for the charity.

But around the 50-hour mark, who should drop by but Rep. Ocasio-Cortez, after tweeting her support for the fundraiser. It was in the midst of a thread started by LGBT activist Charlotte Clymer, in which Ocasio-Cortez hit back at screenwriter Aaron Sorkin, who said on Sunday that young Democrats needed to "stop acting like young people," criticising them for focusing on issues like "transgender bathrooms."

"That’s a Republican talking point they’re trying to distract you with," Sorkin said.

Tweet may have been deleted

Ocasio-Cortez, who recently delivered a perfectly deep Twitter cut with a 20-year-old video game meme, chatted casually to Hbomberguy about Nintendo 64 being "the best system" of them all.

"I never owned a N64 but I used to go to my cousin's house all the time and she had Super Mario 64, Pokemon Snap, and probably a handful of other things," she said.

Tweet may have been deleted

But of course, in an effort to raise awareness for Mermaids, the Congresswoman chatted about discrimination and economic hardship experienced by the trans community.

"It makes these issues much more acute in their crises than they usually are on average for other people," she said. "So it's important that we do talk about these issues in the economic frame, but not let go of the fact that that discrimination is a core reason for the economic hardship."