Sesame Workshop doesn’t like it either. According to a 2011 statement, Bert and Ernie are most definitely not gay. Also, they’re Muppets.
“Bert and Ernie are best friends,” the statement read. “They were created to teach preschoolers that people can be good friends with those who are very different from themselves. Even though they are identified as male characters and possess many human traits and characteristics (as most Sesame Street Muppets™ do), they remain puppets, and do not have a sexual orientation.”