This is Angelina's worst nightmare!

Brad Pitt has been secretly dating gorgeous MIT professor Neri Oxman since last November, and apparently the Hollywood hunk is already head over heels!

"Brad’s absolutely smitten by her. Their chemistry is off the charts," a source dished to Us Weekly.

Page Six was the first to report the news, but they claimed that the pair had a "professional relationship" that could turn into something more. Not so, say insiders!

"They got romantically involved almost right away. He’s been going to great lengths to make sure he’s not spotted by prying eyes. They are very much a couple," the source added.

So how have they managed to keep their love affair under wraps until now?

"Brad has been spotted going into her apartment building on multiple occasions late at night and emerging the next morning after she leaves to teach. Neri doesn’t cook. They have been ordering food in from her favorite restaurants, and Brad has been doing a lot of cooking," the insider revealed.

Sources say they traveled internationally together in February to South Africa for the Design Indaba conference, where the Israeli native was set to be a featured speaker.

The actor was first put in touch with the Angelina look-a-like for help on an architecture project he was working on, and things took off at lightning speed after that.

"Brad had only planned on spending two days at MIT last fall, but ended up staying for a week. Neri invited Brad for dinner at her Cambridge apartment, which is very close to the campus. They got romantically involved almost right away. Neri had been dating a very wealthy man, and dumped him almost immediately," the source explained.

This is the exact type of woman to make Angie seethe with jealousy!