'Glee' Spoiler: Trouble Ahead for Kurt and Blaine?

In the season three premiere of "Glee," we finally saw Blaine (Darren Criss) transfer to McKinley for Kurt (Chris Colfer) and join New Directions, making the Kurt and Blaine (okay, I'll say it: Klaine) thing official.

But, the casting of a new actor on "Glee" might cause some problems later in the season for the new couple. So before we move on, SPOILER ALERT!

The actor in question is Grant Gustin, a musically-inclined stage performer who recently toured with "West Side Story." Gustin will reportedly play a Warbler who has a bit of a crush on Blaine, which could mean trouble for the currently least dysfunctional couple on "Glee."

TV Line reports that Gustin's character, named Sebastian, will be a "male version of Santana." So, a little devious and a bit promiscuous, but probably not dressed in a cheerleader's outfit.

Sebastian will appear in the fifth episode of the season, so we're still a few weeks away from the drama. Better enjoy it while you can, Klaine!