When it comes to celebrity couples making out in public, you'd think all those beautiful people would know how to make a kiss look hot. They manage to do it on-screen with complete strangers, and frankly, a large part of their job is to hook up take after take and make it still look steamy and unrehearsed, right? But as our slideshow-happy friends at Us have shown us, stars are seriously lacking in the hot and heavy PDA department. While some couples (Drew Barrymore and Justin Long) are downright sweet, and some are disturbingly turning us on at such an early hour (Enrique and Anna Kournikova, natch), we'd like to officially ban any future photos of a select few couples getting down and dirty ever again. The good, the bad, and the nauseating, after the jump:

Though inching your digits inside the shorts of your incredibly hot girlfriend may not be the classiest move, we'd watch a porno starring Enrique and Anna any day. As for Drew and Justin, the more photos and TMZ clips we see of this couple, the more we approve. They're cute. Even when they kiss in cars. Which is usually just plain awkward. And so what if TomKat are nutcases? This classic dip Tom pulled off in Rome early on in their relationship is as romantic as it gets.

Oh dear. The boob-grab from behind? While making eye contact with some other chick off-camera? Sorry Billy Bob, but that whole crass thing you made work with Angelina became instantly uncool the second you dumped her. As for this picture of Britney Spears gleefully grabbing K. Fed's crotch on a balcony for all the paps to see, well, even writing a snarky comment on it might make us physically ill. And just in case you didn't think the idea of kissing Nicole Kidman was horrifying enough, Us has thankfully provided us with proof. Yeah, thanks. A lot.

[Photo credits: INF, Flynet, Bauer-Griffin, BE Images via Us, Wireimage]

• CELEBRITY PDA! [Us]