Very simple, and I need help navigating arguments based on paternity tests. The main rebuttal i usually get is "You do not trust your partner" or "Relationships are built on trust, asking for one shatters this rule"

Or if its your significant other, she will reply with "How could you think i would lie, cheat on you, and pass off another man's kid as your own?"

How do I argue that I simply want knowledge that the child is mine, and not based off "claims" of certainty. (e.g. He looks just like you!).