The Brooklyn Nets star was playing the video game “Grand Theft Auto” on a Twitch stream on Monday night. When trolls showed up in the comments section with pro-Celtics messages, Irving took an opportunity to rag on the Celtics fanbase as a whole and the overused jokes he had heard from them. “‘Oh Kyrie, what are you doing at home?’” said Irving in a mocking voice. “That’s how y’all sound to me. ‘Ooh, you’re going home, you going to Cancun? You at home? Ooh Kyrie, you suck.’ “‘What are you doing? Oh my god, go back to Cleveland,’” Irving continued derisively. “‘Oh my god, Boston hates you, oh my god.’ That’s how y’all sound to me. Cockroaches. That’s how y’all sound to me.”