Did Reese Witherspoon and Jake Gyllenhaal have sex on a plane?

Reese Witherspoon and Jake Gyllenhaal may have joined the 'Mile High Club'.

The Hollywood couple allegedly spent more than ten-minutes together inside an airplane bathroom, according to U.S reports.

Witherspoon, 31, and Jake, 26, were flying together from Frankfurt, Germany, to Los Angeles after a trip to the Rome Film Festival.

"Reese was dressed in all black and wearing shades when she and about six handlers entered Lufthansa's first class lounge," an eyewitness told Star magazine.

"It wasn't until she was already on the plane that we realized Jake, also dressed in black, had boarded separately."

After the two-hour flight from Rome to Frankfurt, the lovebirds were transferred to their trans-Atlantic connection on a special bus. Once onboard the group occupied ten out of 16 seats in the first class section of the 747 plane.

"Reese and Jake kissed and cuddled together under a blanket in her recliner seat in the back row," the witness continued.

Three hours into the flight, Reese reportedly got up from her seat and walked forward to the toilet. Two minutes later Jake got up and allegedly walked into the same bathroom. "I started timing them - they were together in there for 11-minutes," the witness told Star.

Jake came out of the bathroom first, and Reese reportedly followed him three-minutes later. "When they each walked by, it seemed like everyone in their entourage took pains to look away.

"Jake worked on his laptop, and then he and Reese took a nap side by side."