The off-screen chemistry of Bollywood stars is often a pale shadow of their onscreen antics.

Kisses between two off screen lovers look like two siblings sharing a peck on screen, while the flirting and physical grappling of non real couples imbue the marquee with unprecedented levels of sexual tension.

Mid-day gives a low-down on what sizzles and what fizzles:

Reel life duds

Vivek Oberoi and Aishwariya Rai in Kyun! Ho Gaya Na

Both Rai and Oberoi exude as much sexual chemistry as two stale fish. And Rais deadpan look certainly doesnt help matters. If their onscreen chemistry (or the lack of it) is any indication of their relationship perhaps Vivek should call Salman Khan and get some love tips from him. Trrrrring! Trring! Its phone time folks!

Chemistry meter: 1/10

Shahid Kapoor and Kareena Kapoor in Fida

Another pair of lovebirds bite the dust! And expectations go bust!

Well on screen at least. After this much-awaited film hit the stands, audiences who had expected hot sparks from the sexy Kareena and teen heartthrob Shahid went home thanda. The coffee was hotter than the passion on-screen

Chemistry meter: 2/10

Bipasha Basu and John Abraham in Jism

Every time Bipasha Basu and John Abraham came together on screen in Jism they sizzled and scorched with their amorous antics. Its a wonder they didnt come out of it with their hair frazzled instead of merely dishevelled.

Chemistry meter: 8/10

The high scorers

Kareena Kapoor and Vivek Oberoi in Yuva

Anjaani met anjaana and they both fell in love in Yuva. Vivek Oberoi and Kareena Kapoors lemon-fresh, zingy, tangy love story burst upon the silver screen and the audience was left gasping for more. But unfortunately after Yuva they havent signed another film together

Chemistry meter: 9/10

Shahrukh Khan and Kajol in Kuch Kuch Hota Hai

This is one couple who can heat up the silver screen with their on-screen chemistry. Whenever Shah Rukh and Kajol come together they make bells jingle, hearts tingle, and love becomes the fashionable again. Timeless chemistry that simply oozes...

Chemistry meter: 10/10

Aamir Khan and Preity Zinta in Dil Chahta Hai

Jaane kyon log mohabbat kiya karte hai? Aamir chopped off the rose but that didnt stop bright, bubbly Preity from falling in love with him. It was ordained that it would happen. Intelligent Aamir and chirpy Preity.

Theirs is the kind of sizzling chemistry that lives on even after three years. Dil chahta hai they keep making many more films together

Chemistry meter: 8/10

Hrithik Roshan and Kareena Kapoor in K3G

Poo (Kareena) and Rohan (Hrithik) in K3G fell in love and lived happily every after. But in real life this was one love story that got derailed after three films.

They were called The Golden Couple on screen and off-screen until papa-in-law, Sanjay Khan, put a spoke in their wheel and insisted that Hrithik get married to dear daughter, Sussanne

Chemistry meter: 7/10