Transit Police report Taha Hamid, 28, of Dorchester, walked into the women's room at Back Bay station around 10:30 a.m. yesterday, pulled his pants down and then relived himself in a sink.

When she objected, police say, he retorted, "This is a man's bathroom now!"

A Transit Police officer who happened to be on patrol in the station at the time quickly corrected that assertion by arresting Hamid on a charge of open and gross lewdness.

Hamid was formally charged with open and gross lewdness following the incident around 10:30 a.m. yesterday, police say.

Innocent, etc.