Divorce from Kelis Turns Nas-ty
05/20/2009 AT 08:00 PM EDT
Kelis, 29, the "Milkshake" singer who's pregnant with their first child due in July, filed for divorce from Nas, 35, last month. Both sides are seeking joint custody of the unborn child.
Although the couple went public with their marriage with a ceremony in 2005, the pair was secretly married at a courthouse in 2003, a source confirms.