Bam Margera is desperate to develop a relationship with his son, Phoenix ... but the former "Jackass" star says his estranged wife isn't having it.
Bam's attorney, Peter W. Thompson, tells TMZ ... Nikki is not allowing Bam to talk to his son through FaceTime or phone calls, and she's completely cut off all contact.
We're told the last communication between Bam and Phoenix was over 2 months ago, on March 29, when Bam came to California to visit his son.