Fuck joint custody,
When the parents divorce the custody of the kid is usually joint, meaning that neither of the parents have legal privileges over the other when deciding for the kids.
This usually means that the child will stay a few days with his father and some others with his mother, without legal restrictions but only based on parents' agreement.
Jay is expressing that he wants to raise his daughter and be in her life more than just part time.
To help improve the meaning of these lyrics, visit “Jay Z Blue” by Jay Z Lyrics and leave a comment on the lyrics box