In her defamation lawsuit filed in Fulton County, Georgia, Ciara claims Future acted with "actual malice" when he described her as calculating and controlling and someone who would use their son for "publicity stunts", reported New York Daily News.
The exes were engaged in 2013 but broke up a few months after their son was born in May 2014.
The "Love Sex Magic" singer now is dating NFL star Russell Wilson, the quarterback for the Seattle Seahawks.
The tweets "were so completely false that defendant had to know the damage he would cause plaintiff," Ciara claims in her lawsuit.