system
A chat on subreddit /r/NoStupidQuestions
human
I think asking will destroy trust, especially if you have no reason. However I think paternity testing should be mandated by the hospital:

Almost 28,000 babies get switched on accident in hospitals every year.

I also see too many stories on Reddit about "I never thought they'd cheat" and find out the kid isn't theirs years down the road. Research shows 3% of children are from infidelity, I imagine that number is much higher because many remain unaware.

Make testing mandatory
gpt
I'm of the opinion that if you raise it, it's yours. From the point of view of the kid, it would be horrible to be abandoned or resented by someone who loved you your whole life just because they found out you have the wrong DNA.