Does it seem like just yesterday that Glee was celebrating its momentous 500th song? Well, it's time to add another hundred candles to that cake, as the show is about to hit song number 600 with a duet from a beloved former couple.

The show reached the 500 song mark last season with Blaine (Darren Criss) singing "Shout" during Season 4, Episode 15: "Girls (and Boys) On Film." At the time, we were shocked that the show had performed that many songs already. But now that the show is just about at 600 songs, 500 seems positively quaint, right?

So who gets the honor of performing the 600th song in Season 5, Episode 9: "Frenemies"? That would be Artie (Kevin McHale) and Tina (Jenna Ushkowitz), who dated back in Season 1 before they moved on to greener pastures with Brittany (Heather Morris) and Mike (Harry Shum Jr.), respectively. But they were pretty darn adorable together, so we can't wait to see their performance.

And which tune will they be doing? Well, according to a rumored song list for the episode, the pair will be singing two songs: Kenny Loggins's "Whenever I Call You Friend," and En Vogue’s "My Lovin’ (You’re Never Gonna Get It)." We haven't yet heard which of those will be the milestone song.

Jenna and Kevin both sound thrilled to be performing together as well. On November 19, Jenna tweeted:

Then, she retweeted this message of Kevin's:

Credit: Instagram

Wait, so these two have never had a duet together? How the heck is that even possible? In other words, it's a long time coming.

Jenna also marked the happy occasion by posting a photo to Instagram of herself with a very cool sign.

"Our amazing A-camera/steady cam operator Andrew Mitchell had this amazing poster made with all 600 songs listed!" Jenna captions the pic of herself holding the "600" sign. "Pretty awesome. #600 #glee."

We can't wait to hear the big song. And if Jenna can go ahead and send us a copy of that 600 sign, we'd appreciate it!

Sources: Jenna on Instagram, Jenna on Twitter, Jenna on Twitter