David Tutera should NOT split up his twin babies -- so says one identical celebrity sibling who tells TMZ if the reality star doesn't come up with a better plan, both of the infants' lives will be ruined.
TMZ spoke with Carlos Ramirez -- the twin brother of Efren Ramirez, who played Pedro in "Napoleon Dynamite." CR tells us if David and his ex Ryan Jurica separate the kids, he believes it could cause a major "identity crisis" later in life.
"Splitting twins is a death in itself," he adds. "Twins grow together emotionally and to not let them connect like that will be damaging."