"Second openly gay man to win an oscar or third or fourth or 100th, It wasn't my point. Apologies for the mix up @DLanceBlack I'll be sure to check out your films now x Belated Congrats on the Oscar x (sic)."
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However, Sam didn't respond to the first part of Dustin's tweet, which warned him to stay away from his fiancé, Olympic diver Tom Daley.
Dustin wrote: "Hey @SamSmithWorld, if you have no idea who I am, it may be time to stop texting my fiancé. (sic)"
Dustin also sent him a link to a video showing him accepting his prize for the movie Milk. Alongside the clip, he wrote: "Here's a start."
The screenwriter took umbrage to Sam's acceptance speech in which he said: "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.
"If is this case, even if it isn't the case, I want to dedicate this to the LGBT community all around the world. I stand here tonight as a proud gay man and I hope we can all stand as equals one day."
- Bang! Showbiz