Lex was feeling like Peppermint Holly had forgotten about him, but apparently she was just waiting for THE perfect moment to mess with him.
“You’re going down, Alexander.
I’ve been waiting for you all night.
I’ve got the advantage,
cause you have no idea I’m waiting for you.”
She picked the perfect sniping spot as well. As soon as she spotted him coming up the stairs, she was ready to shoot.