A man can say “we’re pregnant” as long as he is consistent and says “we’re ovulating”, “We’re menstruating”, “we’re menopausal”, “We love our hot flashes”.
I rather hear a man say “I knocked up the old lady” than hear a man say that he’s pregnant.
“We’re expecting a baby” is the correct term. It makes a man sound like a father and not like some idiot who fakes what the pregnant lady is going through.
Proper response :
“We’re pregnant”
“Really ? Both of you “ ??