Stick it up ya Southside
The chick is asking Schoolboy Q to give her Anal Sex. This is also continuing the use of city locations started in the previous line.
The “Icky, icky icky” would refer to the ensuing dirty sex.
To help improve the meaning of these lyrics, visit “Collard Greens” by ScHoolboy Q (Ft. Kendrick Lamar) Lyrics and leave a comment on the lyrics box