With a single Instagram post, Elton John set metaphorical fire to one of Italy's most illustrious fashion houses this weekend — and literal fire to the Dolce & Gabbana dresses in at least one of his celebrity friends’ closets.

The 67-year-old entertainer posted the following message on Instagram Saturday in response to comments made by Domenico Dolce and Stephano Gabbana about the "synthetic" nature of babies born by in vitro fertilization:

Elton John DG Insta post

John and his husband, Canadian filmmaker and producer David Furnish, have two children who were conceived by in vitro fertilization.

"How dare you refer to my beautiful children as ‘synthetic.’" wrote John in his caption for a photo of the designers. "And shame on you for wagging your judgemental little fingers at IVF — a miracle that has allowed legions of loving people, both straight and gay, to fulfil their dream of having children."

"Your archaic thinking is out of step with the times, just like your fashions," he continued. "I shall never wear Dolce and Gabbana ever again. #BoycottDolceGabbana"

John's disparagement of the luxury brand's "out of step" fashions caused an immediate stir on Instagram, but as more people discovered what had been said to offend the artist, his #BoycottDolceGabbana hashtag spread quickly across the web.

li_IVF baby

Angering many, it wasn’t just in vitro fertilization that Dolce & Gabbana had slammed in a recent interview with the Italian magazine Panorama — it was gay adoption itself.

"We oppose gay adoptions. The only family is the traditional one … No chemical offsprings and rented uterus: Life has a natural flow, there are things that should not be changed," said the designers, according to an English translation of the interview, which was released this weekend.

"You are born to a mother and a father — or at least that’s how it should be," said Dolce. "I call children of chemistry, synthetic children. Uteri [for] rent, semen chosen from a catalog."

This is not the first time the designers, who are both gay, have spoken out against the idea of gay adoption.

"I am opposed to the idea of a child growing up with two gay parents," said Gabbana in a 2006 interview with another Italian media outlet. "A child needs a mother and a father. I could not imagine my childhood without my mother. I also believe that it is cruel to take a baby away from its mother."

Elton John and David Furnish

Elton John, left, and David Furnish arrive at the 2014 Elton John Oscar Viewing and After Party in March 2014, in West Hollywood, Calif. (Richard Shotwell/Invision/Associated Press)

Still, many online were upset to learn via John’s Instagram post Monday that Dolce & Gabbana’s lead figures held these views.

Twitter has been seething with criticism of the fashion billionaires in the wake of John’s Instagram post, as celebrities, LGBT activists and fans alike offer up their support.

As of Monday morning, the #BoycottDolceGabbana hashtag was trending worldwide.

Singer Courtney Love was one of the first stars to amplify John’s hashtag on Twitter by encouraging her followers to "boycott senseless bigotry" and stating that she wants to burn all of her Dolce & Gabbana clothes.

American screenwriter Ryan Murphy (of Glee and American Horror Story fame) also used the #BoycottDolceGabbana hashtag to criticize the design team’s "horrifying views."

British fashion designer Victoria Beckham, singer Ricky Martin, and actor/TV host Dominic Monaghan, among others, joined the fray.

John’s star-studded support system has helped boost his message, but the most powerful tweets on the hashtag might be those from Twitter users who have welcomed a child or were born with the help of in vitro fertilization.

In response to all of the backlash against their eponymous label, the Dolce & Gabbana designers issued a statement on Sunday saying that their comments were not intended to "judge the choices made by others."

Dolce told the Associated Press that his views were simply based on his own experience growing up in a traditional Sicilian family "made up of a mother, a father and children. I am very well aware of the fact that there are other types of families and they are as legitimate as the one I've known."

"We do believe in freedom and love," said Gabbana — though his Instagram account shows little love for John and the boycott he sparked.

@StephanoGabbana has posted dozens of Instagram screenshots from fans supporting his controversial comments since Sunday, many of them including the #boycottdolcegabbana hashtag, heart emojis or the words "la liberta di pensiero" (which roughly translates to "freedom of thought.")

On Monday, the designer highlighted what appear to be his own comments on John’s original Instagram post: "Fascista!!!" the comments read. "#boycotteltonjhon [sic]."

While only time will tell if Dolce & Gabbana’s comments hurt their label’s bottom line, some on Twitter have already made it a point to publicly throw their (rather expensive) Dolce & Gabbana pieces in the trash.