Say it ain't so, Stefan!

Based on the official CW promo for "By the Light of the Moon," it's seem very clear that this character betrays Elena in the worst way on this week's installment of The Vampire Diaries: by getting it on with Katherine.

But that can't really be the case... can it? Teases Elena Dobrev in a new interview with EW:

With Elena away, will Stefan play.. with fire?

"The line between love and hate truly is very, very thin... [Katherine] has a chance to egg him on, and he can’t do anything about it. He has no choice but to listen, and yeah, it is a very kind of sexy, manipulative scene, and he gives in. It’s pretty crazy.”

Sounds like Statherine sex confirmation to us, doesn't it?

As for the dilemma Elena faces - should she sacrifice herself to save her loved ones? - Dobrev says Elijah will enter the picture this week and make things even more complicated:

“Elena is in a predicament in the sense that she has a challenge, and she is out of control for the first time in a long time. When Elijah comes into her life on this day, it’s even more challenging, and tempting. Elena is the one who has to make a decision, and this time, she’s not in control, which is very frustrating for her. Elena doesn’t like to not be in control.”

With The Vampire Diaries going on hiatus until late January after this episode, can Dobrev give us a tease of what to expect in 2011? Possibly one related to The Originals?

“It’s gonna keep getting gorier and better and darker. It adds a whole other layer. As difficult as it was for all the characters before, now they’re faced with an even more epic danger. Everyone is at risk.”

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.