Ooo, we're past the Kiss close now

This weekend we spent 5 to 6 hours making out in the car, and talking ... I fingered her, and kissed her on the back and the neck, practically got her naked. Although we didn't had sex, I could, but I wanted to be comfortable.
The hotel room is booked and we're set for the weekend, bringing a bottle of alcohol, and spending the night. We both know we're going to have sex. According to her, she has only had sex one time with her boyriend in almost 2 years of relationship. She always told me to leave my girlfriend and that she would leave her boyfriend, but I never did, now that Im single, Im pretty sure she will leave her boyfriend. I mean, she doesn't even hide it, we flirt on facebook, through wall posts, that her boyfriend can easily see. I don't know if she's making it so the guy leaves her by seeing that, but I mean, its ruthless flirting through facebook on and on.
She says she feels sexy again with me, that her boyfriend made her lose all that. She feels attractive and desired once again.
She has on facebook a relationship with him, but he doesn't has her back, how long should I wait before I tell her about this??
SHe says she is pretty excited about being with me, that she likes me A LOT, and loved the way I kissed her.
I was thinking of waiting maybe till the 14th of february to ask her about the boyfriend, I don't know if she wants to wait till after the 14th to break up with him.
But, how long should I wait to confront her about it? Or should I just let it be...