TOMMY LEE is no stranger to sex videos, but this time, he didn't MEAN to have his passions recorded . . .
Tommy was flying first class on American Airlines the other day when he went to use the bathroom. But he wasn't alone. His girlfriend BRITTANY FURLAN went in there with him.
Another passenger noticed, and started recording the bathroom door. Eventually, Tommy came out . . . by himself. And less than 30 seconds later, Brittany made her exit . . . with a big grin on her face. (Here's the video.)