Pauly D -- Baby Mama Won't Let Me See My Baby Alone

Pauly D has just been REJECTED by his baby mama ... who says she will NOT let him visit his 5-month old daughter unsupervised.

Pauly's lawyer sent a letter to Amanda Markert's attorney, requesting that Pauly get visitation of the little girl, Amabella, for 2 weeks beginning today.

TMZ has learned ... Markert's lawyer told Pauly's mouthpiece to pound sand, saying Pauly cannot take the baby unsupervised for that period of time. So it seems she might be open to visitation if she or someone else she chooses is present.

Our sources say Pauly D's lawyer has agreed to supervised visitation but now all they're getting is radio silence.

Pauly's rep tells us, "Paul and his entire family are eager to meet and spend time with Paul’s daughter. Paul has been requesting visitation for quite some time now, but his requests have either gone unresponded to or denied. He and his family are committed to being a significant part of his daughter’s life and are excited to make that a reality. "