After weeks racking up awards for her Black Swan performance, it's no surprise that pregnant Natalie Portman would want to get away from it all.

The Oscar winner, 29, and fiance Benjamin Millepied, 33, packed their things and headed to Napa Valley for a romantic wine country weekend.

And Portman, who'd been a red-carpet stunner all season with her maternity style, went an entirely different direction for the trip.

"They were really low-key," a witness tells Us. "She was in sweats!"

For all the details on the couple's romantic get-away, check out this week's Hot Stuff video, as explained by Senior Editor Ian Drew and Basketball Wives star Jennifer Williams.

Also in the roundup: Rob Pattinson and Kristin Stewart's steamy Vancouver love nest.