Dr Ihab Mohamed Fouad Anwar faces a disciplinary hearing concerning claims he also rubbed his pelvis against the same passenger on a vehicle in Glasgow.
A Medical Practitioners Tribunal Service (MPTS) hearing in Manchester began yesterday, at which the full charges against the surgeon, who practises in Colchester, Essex, were revealed.
According to the allegations, the medic exposed himself during a Glasgow coach journey, which took place between March 1 and 2, 2012.
The doctor's actions were "sexually motivated", according to the MPTS.
The doctor, who received training at the University of Alexandria in Egypt, and qualified in "general surgery" in 2007, is suspended but could be struck off if the allegations are found proved.
The hearing, which is being chaired by Peter Schofield, continues.