Sure, he fathered and is apparently raising some kids of his own. But...
That doesn’t make him Shiunna’s parent, just her mommy’s boyfriend.
That doesn’t mean that your standard for being a parent (youy become one the moment after you set up house with mommy and start giving her the big shtupp) makes any sense.
He and she are parents...he’s there acting as one...maybe not the ‘baby’s’ parent biologically or legally but I would guess they both are acting as parents to all the children who live with them....Can we move on now.