CHICAGO (CBS) — A man was arrested late Monday night, after allegedly exposing himself and rubbing against a woman on a CTA bus.

Police said the woman, who is in her 20s, was about to exit the #29/State bus at 500 E. Illinois St., near Navy Pier around 10:30 p.m.

As she stood in the aisle, waiting to exit, another passenger – a man in his 40s – stood up behind her, exposed himself, then rubbed himself against her.

The woman screamed, the bus driver stopped, and police arrived moments later.

Officers arrested the man, but charges were still pending early Tuesday.