But who is it?
'Avengers: Endgame' featured a minor character - played by director Joe Russo, nonetheless - speaking about the breakdown of his same-sex relationship following the Snap in an early scene of the movie.
This small moment was the first openly gay character in the Marvel Cinematic Universe, but according to Anthony and Joe Russo, he isn't the last. In an interview with EW, the directing duo explained that another Marvel character has been gay the whole time. The reveal came about during a discussion about the scene in question, when Joe Russo was asked if he was indeed the first openly gay character in the MCU.
"Yes, openly gay," said Russo, stressing the 'openly' part. "There’ve been insinuations about other characters’ sexuality, but this is the first openly gay character." When asked which character it was, Russo said that we would eventually find out and moved on from the topic.
At least one character that we know of was almost revealed as bisexual, so it's not exactly much of a shock. A scene from 'Thor: Ragnarok' indicated that Valkyrie - played by Tessa Thompson - was bisexual, but was ultimately cut from the movie.
Marvel has been pushing for more inclusion in their movies, but it's nothing new in the source material or in comics in general. For example, Psylocke and Pyro from the 'X-Men' comics were both LGBT, and many DC Comics - including Batwoman - have also been confirmed as members of the LGBT community. In fact, the upcoming live-action TV series based on Batwoman will see the lead character played by Ruby Rose, who is a gay woman.
'Avengers: Endgame' is currently in cinemas.