Blueface 'Rescues' Newborn At 4 AM, Says Chrisean Neglected Him For Sex

Blueface says his fatherly instincts were forced to kick in early in the morn ... this after he allegedly got word that Chrisean had left their son in the care of her BFF.

In the wee hours of Monday, Blueface went live on IG while holding his son, Chrisean Jr., and appeared to have taken the infant from Chrisean's friend Marsh ... who was on the phone attempting to contact someone. It looks like she was babysitting the kid for mom.

Blueface claims Chrisean abandoned her motherly duties for a booty call ... called the entire scene irresponsible on her part -- labeling her a "booth bitch" for allegedly ditching their kid in the middle of the night.

The "Thotiana" rapper's anger didn't end with Chrisean ... he promised Marsh that his fiancee Jaidyn Alexis was waiting for her at another destination to give her the beats, but the camera cut off before any such violence could be captured.

Chrisean has yet to respond to BF's bad parenting claims but she did post her latest tracks after being up late in the studio -- juggling mom and rap life has its challenges!!!

The last time we spoke to Cardi B, she gave Chrisean life nuggets on how to balance motherhood and her personal life.