MORNINGSIDE HEIGHTS, Manhattan (WABC) -- A 53-year-old man was stabbed after exposing himself to a homeless man on a subway overnight Thursday.The men were riding a southbound No. 1 train, near the 116th Street Columbia University station in Morningside Heights, at around 1:30 a.m.According to the New York City Police Department, when the victim exposed himself to the homeless man, the homeless man responded by stabbing the victim.The victim was taken to the hospital with a non-life threatening injury.The 20-year-old homeless man was taken into custody. Charges are pending.