I have never played the game, but The Last of US is a show based on a video game and the gay scenes were in the video game from everything I’ve read.
From that perspective I can understand why the scene was in the show.
I never played it either. The producers said they were going to follow as closely to the game story as they could.
No, I've played the game, the ONLY reference to 'gay' is that gay guy A discovers gay guy B has hanged himself because he became bitten/infected by a zombie, no other reference/scenes and zero gay sex crap in the game.