What appears to be a tongue-in-cheek social media movement to mark June 29 as a day to celebrate heterosexual pride has become one of the day's top online trends.

Hundreds of thousands of tweets have been sent Wednesday with the hashtag HeterosexualPrideDay.

The idea of such a day has outraged many. One of the top responses comes from British comedian Dapper Laughs, who rhetorically asked on Twitter, "What's next, #BreathingAirDay?" Others have flooded the hashtag with gay pride memes and other mentions of support.

The Twitter user who first tweeted it declined to comment to The Associated Press. It's not clear if the account's intent was serious or satire, but there appears to be no formal heterosexual pride day.

President Barack Obama has proclaimed June as LGBT Pride Month.