While we are totally swooning over the jaw-dropping gorgeousness of Aishwarya Rai Bachchan in the scenes from 'Ae Dil Hai Mushkil', her chemistry with the chocolaty heartthrob Ranbir Kapoor is setting the temperature up high. We can't help but gape at the sizzling scenes from the trailer and songs which show Ranbir and Aishwarya in a totally different light. However , it does make us wonder that how exactly did they make the scenes come so alive on screen? They look so good together, it is almost unbelievable that they haven't been casted in films already. But here's the catch, the preparation for this film started almost 10 years ago. Ranbir Kapoor and Aishwarya Rai Bachchan.... Wait, this isn't an update on their upcoming film Ae Dil Hai Mushkil. Writer Rumy Jafry shared this throwback picture of the two actors on Twitter and now, it's viral: https://twitter.com/rumyjafry/status/780727990309093376 This picture is apparently from the time when Ranbir assisted his father Rishi Kapoor on 1999 film Aa Ab Laut Chalen (Mr Kapoor's first film as director) which featured Aishwarya Rai. It also starred Akshaye Khanna and Rajesh Khanna. Mr Jafry wrote the film's story and dialogues. Aishwarya, 42 and Ranbir, who celebrates his 34th birthday today, are all set to co-star in Karan Johar's 'Ae Dil Hai Mushkil', his directorial venture after a hiatus of four years. Ever since the release of the film's trailer and song 'Bulleya' fans cannot stop raving about Ranbir and Aishwarya's fabulous jodi. They indeed make quite a pair in the film and have some pretty bold and unflinching scenes: