I'm sorry, but you are not really their mom. Your husband must have sucked the woman he's cheating with's eggs into his penis and fertilized them there, then shot them back into you. If you keep it a secret, nobody will know.
If your interested in making the baby become yours biologically, you can follow these steps:
Wash the child in mustard
Let them soak in warm water for 3 days
Sacrifice five roosters
Poor a drop of your and your husband's blood onto the infant
Insert the child back into yourself
Proceed to engage intercourse with your husband
Re-birth the child
Your child is now biologically yours!
This takes alot of time and it's easier to just pretend the child is yours, but it's worth it.
I hope this helps! :)
30 years of medical school