Sesame Street writer, Mark Saltzman, shared with TMZ that when he wrote the characters of Bert and Ernie he did envision them being gay and modeled them after his own gay relationship. Saltzman has been with the show since 1984 and was having a relationship with a film editor.
The two puppets have been in the spotlight regarding their sexual orientation for years now. In 2011, a petition swarmed the internet to allow Bert and Ernie to get married to which producers of Sesame Street shared that they were just best friends and nothing more.
Even with the writer coming forward saying yes they are gay, Sesame Street is still denying the statement saying "they are puppets and have no sexual orientation".
Sources: CBS 12 and TMZ