How do I deal with this?

My baby daddy and his mom keep saying very passive aggressive things around me such as: our son gets his good looks from his dad... another example is, they say stuff like his smartness just runs in his dna... his eyebrows come from his dad.. when they're obviously mine. Okay... I can admit.. my son is a spitting image of his dad. But fuck.. im sitting there looking like a dummy while his mom is shooting me those annoying comments. What should I do?