Elphaba had no idea why Galinda had dragged her away from the Ozdust Ballroom.
After all, Fiyero was there.
The emerald girl couldn't see why Galinda would want to be with her and not Prince Charming.
When they reached their floor, Galinda pushed Elphaba against the wall, and the movement caught her green roommate by surprise.
And then Galinda did something that shocked her even more; she kissed her.
Elphaba pushed Galinda away from her, "Galinda! What the hell are you doing? What about Fiyero?"
Galinda kissed the green lips again, before saying, "Forget about Fiyero, I want you"
So Elphaba let Galinda have her.