Cute little blonde that pops out of the Professor's office?

It's just after the museum scene. He's flustered and obviously trying to hide something, and she comes out all fluttery and embarrassed, and they both thank each other, obviously having just engaged in sex.

Anyone recognize her? I think the Prof calls her 'Chris' or something, but I can't find her name in the credits. I also didn't see the first part of the film, so forgive me if I am asking something obvious.

She looks awfully familiar, but I can't recall where I've seen her before.
She's wearing a snug maroon scoop-necked top, a black string choker necklace, and her hair is all combed straight back in a feathery-rooster tail bob, and tied up with a thong.