Smith originally referred to Tyler as his "motherf***ing boyfriend" while talking to the crowd during his performance at a festival in California.
He then tweeted: "Yup @tylerthecreator I Told Everyone You Can't Deny It Now. (sic)"
Tyler replied: "Hahaha you a crazy n***a man."
Smith's tweet telling Tyler he had broken the news to everyone has now disappeared from the 20-year-old's Twitter account.
Tyler's response, however, remains published.
Social media footage shared earlier this week shows Smith, the son of actors Will Smith and Jada Pinkett-Smith, talking to his audience at Camp Flog Gnaw, a festival curated by Tyler in Los Angeles.
"I just wanna say Tyler, the Creator is the best friend in the world and I love him so f***ing much, and I wanna tell you guys something," Smith said during his set.
"Tyler doesn't wanna say, but Tyler is my motherf***ing boyfriend, and he's been my motherf***ing boyfriend my whole motherf***ing life. It's true! Tyler is my boyfriend."
Tyler is seen in the clip shaking his head and laughing.
It's unclear whether Smith and 27-year-old Tyler are actually dating.
Tyler has faced heavy criticism for his use of homophobic slurs in his song lyrics in the past.
In 2015, however, the rapper tweeted: "I tried to come out the damn closet like four days ago and no one cared hahahhahaha."
His latest album includes some discussion of his sexuality through lyrics such as "I been kissing white boys since 2004".
Smith is known for his gender-bending fashion style and has proudly defended his androgynous sartorial tastes.
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