Can I baptize someone else's child?

[Mater]

I have a relative who has ceased practicing his faith and has married a non-Catholic. They have no intention of baptizing or raising their child in the faith or in any religion. May I baptize the infant without their knowledge or consent when I am babysitting the child?

 

[Michelle_Arnold]

No. Such a baptism would be illicit. The only time when a child below the age of reason may be licitly baptized without his parents’ knowledge or consent is when the child is in immediate (not imagined or presumed) mortal danger of death.