These aren’t good arguments at all. Is adoption also “playing house” because the parents are not biological? Doesn’t make sense.
I was thinking the same thing. My wife and I have two adopted sons and I'm sure they consider us their "real parents."
You could turn this argument around and argue that a biological father who deserts the mother before the child is born is a "real parent." That wouldn't make any sense at all.
That being said, the caption under the picture of Cheney's grandchild could have said "Cheney celebrates, along with his daughter's partner, the birth of Mary's child..."
Agreed. Weak argument.