Why is Justin Sun so obsessed with Vitalik Buterin? He’s been razzing him all over Twitter—and on Wednesday he turned up at one of his live speeches, just to put in another little dig.

Ethereum founder Vitalik Buterin made an appearance at Token 2049—the premier cryptocurrency event in Hong Kong—to discuss the next stages for the blockchain platform. Some 1,000 people were in attendance, and Buterin took to the stage like a rock star. It was standing-room only.

Ethereum may be the second largest cryptocurrency by market capitalization, but it’s been taking fire from critics and competitors. Many of the platform’s leading voices have taken to the stump to talk about how it can succeed at scale.

But despite Buterin’s best intentions, he can’t seem to shake the unwanted attentions of Justin Sun, the founder of Tron, a rival cryptocurrency platform aimed at the gaming industry. Tron recently acquired BitTorrent, the renowned peer-to-peer, file-sharing service that was the world’s first, widely used decentralized network.

On March 13, Sun entered the ballroom-turned-crypto hub with a person dressed as an avocado studded with Tron branding—of course such costumes exist. The avocado, for those of you who haven’t been riveted by the Sun-Buterin Twitter squabble, was an allusion to a particularly weird interchange the two had had a few weeks ago.

So there was Sun, just standing there next to a dude in an avocado suit, watching Buterin’s  twenty-minute speech. He was getting noticeably bored. He was yawning. It was quite rude—or would have been, had anyone noticed. But as it turned out, the only rise Sun got from the crowd, which included such grandees as Bitcoin trader and meat-eater Tone Vays, was a couple of laughs when he and the avocado sauntered in.

Still, the fluorescent-green avocado, which clocked in at five foot ten inches, was hard to miss throughout the speech.

If Buterin saw any of this, he gave no indication. He never even uttered the word “avocado” during his speech, nor afterward.

So what the hell was that all about? Decrypt caught up with Sun afterward to ask.

Three words, said Tron’s top man: Proof of stake.

Seriously.

“I do not think that Ethereum is ready for a change to Proof of Stake at all,” Sun said very seriously as he stood next to the Tron-festooned avocado. The avocado was silent.

Sun continued his tirade: “Even for a year or more, Ethereum won’t be ready for a proof of stake [integration] at all.”

Furthermore, continued Sun, who was apparently just getting started, it is his firmly held belief that the latest Constantinople upgrade simply kicks the can down the road, that the “difficulty bomb,” which transitions the platform to proof of stake, still needs to be addressed. And, he asserted, meanwhile the community of miners and devs and users is in turmoil.

Sun called these conflicts “constant,” adding that when “certain concepts about staking” are brought up, “a lot of debate” ensues.

The avocado said nothing.

And soon, he and the Tron founder wandered away—presumably, to stalk Buterin evermore.