It’s not a dumb question! In my AU, pretty much anyone can both become pregnant and impregnate others, which was mainly something I implemented for the sake of fankids. Unlike in some versions of omegaverse, I chose to base parental titles on gender rather than who bore the child since I realized it would get a bit confusing otherwise (one child calling a parent ‘dad’ while their sibling calls the same parent ‘mom’ for example). So with that in mind, N is the father to all his children! Just like Hilbert is also the father of their kids. Both are the dads.

However, if you’re referring to actual pregnancy here, then yes, N was the one pregnant with Oliver, while Hilbert had the twins. Hope this clears things up!