Hong Kong police are investigating after viral videos emerged showing two men having sex and masturbating on an MTR train.In one 45-second clip, the naked pair are seen cavorting in an empty train carriage on the Tung Chung line. Clothes are strewn on the seats.One of the men is also seen in another 30-second video taking a selfie in what appears to be the same carriage. Passengers can be seen sitting at the far end of the train.In both videos, the faces of the men were digitally obscured by…

This post was originally published on South China Morning Post.