Nas claims Kelis has been anything but accommodating when it comes to giving him time with their 8-year-old son ... and he's asking a judge to help him out.
Nas calls Kelis "hostile" in court docs, obtained by TMZ, claiming he's tried for months to work out an amicable agreement for sharing their son Knight ... and Kelis just won't cooperate.
He's asking a judge for Knight on the first, third and fifth weekend of each month from Friday after school through Monday morning.
Nas claims Kelis has dictated when, where and for how long he's able to spend time with his son ... and he's had enough.
The two have been locked in multiple legal disputes since their divorce in 2010.