Dont be gay meme

Be Gay Do Crime is a catchphrase and protest slogan used by activists, members and allies of the LGBTQIA+ community, promoting freedom from discrimination on the basis of sexual orientation or being non-cisgender.

Far as I know, it dates back to an old comic in a cartoon that says "be gay, do crime" and I know no other context other than it was from the time way back when, when gay was often used to describe happiness.