Probably not on someone's lap, but this last trip my 4yo daughter had sat in a seat at the end of the night, and I was standing because I had my 1yo daughter in a carrier on my back, asleep. A mom with her kid came in, so I told her to sit beside my daughter. Well, my daughter ended up falling asleep, so the other mom had to put her arms around my dd to prevent her from falling. I appreciated the help...