Glee star Lea Michele paid tribute to her late boyfriend and co-star Cory Monteith with a touching Twitter post today.

Cory died of an accidental drug overdose in July 2013, between the fifth and sixth seasons of Glee, in which he also starred alongside Lea. He would have turned 33 today, and the actress marked what is no doubt a difficult date for her with a message on social media.

Sharing a picture of Cory sitting at a drum kit and smiling, Lea wrote, "I know you're serenading everyone right now.. We love you Cory! Happy Birthday…"

I know you're serenading everyone right now.. We love you Cory! Happy Birthday.. pic.twitter.com/pbjMFOr06N

— Lea Michele (@msleamichele) May 11, 2015

Lea and Cory had been dating for over a year when he passed away over two years ago, having met when they both began work on Glee in 2009. Their characters, Rachel and Finn, had an on-off relationship throughout the first four seasons of the show.

Back in February, Lea paid another quiet tribute to Cory as Glee wrapped filming on its final ever episode. Posting a picture of herself walking off the show's set carrying Finn's McKinley Titans football jersey, Lea simply wrote, "One more thing…"

The actress and singer remained out of the spotlight for several weeks following Cory's death, and later admitted she believed she had found The One with him.

"We were done. We were it. When you’re at that place in your life with someone, you talk about everything," she told Glamour UK of her relationship with the actor. "We talked about a lot of things. We talked about children and what we would look like when we grew old and who would be fat and how we would stay thin. We talked about where we wanted to go and what we wanted to do."

Last year Lea began dating aspiring actor Matthew Paetz, and now shares a home with him in Los Angeles.

Speaking about the possibility of moving on from Cory, Lea said she knew it was what he would want. "[P]eople have to understand that I can’t be alone forever. Cory wouldn’t want that," she said.