Need help putting someone in their place!?

I have two children with my partner. his parents insisted that he have a paternity for our first child despite the fact that they looked identical. My partner denied the paternity in court because he had no doubts it was his son. now we just had our second child and this babe looks like me this time and again his parents want a paternity done. they are paying for it and i told my partner that we should just take the test to shut them up. so we are going to take the paternity. after all is said and done and the results are back positive that he is in fact his father i want to say something to his parents. but im not sure what. i want it to set them straight that it hurts me that they assume im a whore and that it hurts my partner that they under estimate his judgment. any suggestions on what to say?