After the Oscars, Sienna Miller and her boyfriend Rhys Ifans just couldn't wait until they got home to do it. So they had sex in first class, or so the Mirror reporter who apparently witnessed the whole thing would like to think. The Mirror gives us the details like a bad romance novel or press release; we're not sure which.

The pair's antics reached an eyepopping climax - at 37,000ft - with Rhys whipping off his top and jumping half-naked into giggling Sienna's fold-out SINGLE bed.

Their award-winning transatlantic performance (in the horror category) started from the moment we'd buckled into our Upper Class seats for the 7.30pm Virgin flight on Monday.

Oblivious to all fellow passengers - including Oscar-less James McAvoy, who was buried in his sudoku book - Sienna and Rhys began snogging, tongues a go-go. Imagine a soundtrack of slurping and squelching.

Next came an interlude of hairstroking, petting and nibbling, interspersed with whispering to each other and laughing hysterically.

After slipping into baggy black sleep suits they then treated us to some play-fighting. After a while, Sienna demanded: "Baby, baby, can you go to the bar and get me some white wine." Rhys nodded, collected two generous glasses of Pinot Grigio, and managed to spill one down himself. Classy.

And just as we thought things couldn't get any more stomach-churning, came a sight we wouldn't wish on our worst enemies.

Rhys pulled off his wine-soaked top, exposing his scrawny white body, and squeezed into Sienna's bed for a snuggle. As it's only 33ins wide, that's some squeeze.