In No Strings Attached, the romantic comedy out in theaters today, Natalie Portman and Ashton Kutcher have a lot of sex. That is, in fact, the premise of the movie: two people who really like each other but who have opted not to date, having lots and lots of sex. (Will they fall in love? Wait and see!) It’s been a particularly randy couple of months for Portman: In addition to Kutcher, Portman’s had an onscreen oral-sex sesh with Kutcher’s That ‘70s Show co-star Mila Kunis in Black Swan, rubbed up against Vincent Cassel in the same film, and got knocked up in real life by a person who, as she was so quick to point out at the Golden Globes, “totally wants to sleep with me!” With all this overheated Portman action going around, we figured this was as good a time as any to dig deep, go to the videotape, and assess: Which of Portman’s onscreen sex partners did it best? In retrospect, she hasn’t had the best luck.