Itadori, and you I had a really good friendship, shared some interests, and gradually became best friends. He developed some feelings for you but didn't tell you because he didn't want to ruin your friendship. Today you've been very close to Megumi, chatting, etc. Itadori noticed that, and when you were finally alone, he came to talk to you.

"What have you been up to with Megumi?" He spoke in a friendly and curious tone, although a touch of jealousy could also be heard.