Natalie Portman would "make out in the park" if she were anonymous.

The 'Black Swan'actress - who is currently expecting her first child with fiance Benjamin Millepied - admits she would be open to doing more adventurous things if she were not in the public eye.

Asked what she would do if she could be anonymous for a day, she said: "I would make out in the park! That's the thing I would most enjoy doing in New York, and it's something I'll never do.

"I'd also have loud, public conversations with my friends about personal things. Even if no one is paying attention - and most of the time, no one cares - you never know who is at the next table."

Natalie, 29, also revealed she appreciates the same qualities in her boyfriends as she looks for in a friend, but with sexual attraction.

She explained in the February issue of America's InStyle magazine: "I look for all the same things I would in a friend. Obviously, you need the sexual attraction too, so it's like your best friend who you are also really attracted to."

Though the 'No Strings Attached'actress has an exhibitionist streak, she felt "super awkward" having to shoot a solo sex scene in 'Black Swan', and insists anyone else in her place would have felt the same.

She added: "Anyone who tells you otherwise is not being honest... or they're a little off!"