Dustin Lance Black Slams Sam Smith for Claiming to Be First Openly Gay Oscar Winner, Tells Him to 'Stop Textin

This video is unavailable because we were unable to load a message from our sponsors.

If you are using ad-blocking software, please disable it and reload the page.

Sam Smith's acceptance speech for Best Original Song at Sunday night's Oscars might have had the best intentions, but it definitely didn't sit well with everyone.

After the 23-year-old British crooner remarked that he might be the first openly gay man to ever win an Oscar while accepting the award for Best Original Song, fellow Oscar winner Dustin Lance Black blasted him on Twitter. Black's dig also took on a personal note, when the acclaimed screenwriter brought up his fiance, 21-year-old British diver Tom Daley.

"Hey @SamSmithWorld, if you have no idea who I am, it may be time to stop texting my fiancé. Here's a start," Black, 41, tweeted alongside a video of his memorable acceptance speech in 2009 for his Best Original Screenplay win for Milk.

WATCH: Sam Smith Says He Should Never Have Fallen in Love With His Ex

"THE POINT: knowing our LGBTQ history is important," Black added on Monday. "We stand on the shoulders of countless brave men and women who paved the way for us."

On Sunday, Smith dedicated his award to the LGBT community.

"I read an article a few months ago by Sir Ian McKellen and he said that no openly gay man had ever won an Oscar, and if this is the case, even if it isn’t the case, I want to dedicate this to the LGBT community all around the world," Smith said. "I stand here, I stand here tonight as a proud gay man and I hope we can all stand together as equals one day. Thank you so much."

Smith was making reference to McKellen's interview with the Guardian in January, in which he said that no gay man has won the Oscar for Best Actor. McKellen was addressing the Academy's diversity issue, which was a centerpiece of Sunday's ceremony.

Smith was eventually informed backstage that he actually isn't the first openly gay person to win an Oscar. The list of winners also includes Broadway legend Stephen Sondheim, filmmaker Bill Condon, Melissa Etheridge, Elton John, and lyricist Howard Ashman, who won two Best Original Song awards for his legendary work with Disney.

When a reporter mentioned that Ashman had previously won, Smith did not recognize the name.

"I should know him. We should date," Smith quipped, seemingly unaware that Ashman died from complications from AIDS in 1991.

WATCH: EXCLUSIVE -- Sam Smith Talking About Weight Loss Is Incredibly Refreshing: 'I Love Food So Much!'

Watch the video below to see Smith's performance of his Oscar-winning song, "Writing's on the Wall," on Sunday night, which he co-wrote with fellow songwriter Jimmy Napes.

Related Gallery