Responses
poor translation. Korean men refer to women around their age but older as "Noona". It doesn't mean they are blood-related its interchangeable.
Just like "hyung" for "older brother" younger males call slightly older males.
Thats why most translations would just keep the word "noona" and leave a note rather than literally translate it as it would confuse readers due to the cultural difference.
Just wait for next chapters girls. SPOILER
That kid is not his kid and that hoe just screw around with others too. Actually king's charchter development is so good! He turned a dog for his wife. Really.