Asim Mahmood of Wilson Drive, Wembley , appeared at Westminster Magistrates' Court on Monday (January 16), but did not enter a plea.
He is due to appear at Blackfriars Crown Court on February 13, 2017.
The incident was reported to have happened on a train at Stanmore tube station on Saturday (January 14) involving three women and one teenage girl.
Mahomood was charged on three counts of sexual assault on a female and four counts of exposure, on Sunday (January 15).
He had been arrested the day before by British Transport Police officers.
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