Sienna Miller and Rhys Ifans apparently left fellow passengers amazed as they openly frolicked during a 12 hour flight home from the Oscars.
Fellow passengers said that the actress and the 'Notting Hill' were unable to keep their hands off each other from the moment they boarded a London bound plane in Los Angeles.
One onlooker told Britain's Daily Mirror newspaper, "They were cavorting for almost the entire flight. They kissed each other passionately, before stroking each other's hair, nibbling, whispering and giggling with each other".
During the flight, Rhys even stripped off his shirt after spilling wine all over it.
Passengers claim that the passion, part of which took place on Sienna's fully reclined seat was only interrupted when a flight attendant served them dinner.
Sources say the pair are so smitten with each other that Rhys is planning to propose. The 39-year-old star is said to have hidden a number of marriage proposals in several boxes of Sienna's favorite perfume, which she is taking to Los Angeles where she is filming her new movie, 'GI Joe' next month.
A source revealed, "He stuck a marriage proposal at the bottom of each bottle using a secret system of letters and numbers, because her new film involves her deciphering codes. He loves his ingenious plan and hopes she cracks the code and he gets the answer he wants!".