It’s been exactly one month since Cory Monteith (Finn Hudson) was found dead from a heroin overdose in a Vancouver, B.C. hotel, and his absence is still being felt every day. Most recently, fellow Glee star Mark Salling (Noah “Puck” Puckerman) celebrated his birthday — without his bud Cory by his side.

“Cory 's presence was definitely missed,” a source told InTouch Weekly about Mark’s bash. “Cory never missed one of his birthday parties. They were extremely close. It was definitely bittersweet for Mark.”

The early birthday party — Mark turns 31 on August 17 — was hosted at Hollywood nightclub AV last Friday night. The InTouch source added that Mark and a group of friends, including 90210 and The Lying Game’s Ryan Rottman, arrived around 11:30 p.m. and were “greeted with sparklers.” Festive.

The group “had a good time” despite the glaring absence of a dearly departed friend. As hard as it is to deal with the loss of someone as special as Cory, we can look to Lea Michele’s (Rachel) recent Teen Choice Awards speech for guidance: “Cory reached out and he became a part of all our hearts and that’s where he will stay forever.” Amen, Lea. Amen.

Source: InTouch Weekly