One of these days, I'm going to make a list of words and phrases that I really hate and that I wish people would quit using. It will be a very long list.
One of the items on the list will be men who say "we're pregnant" when referring to the fact that he and his wife or girlfriend are expecting a baby. Aside from being biologically impossible, "we're pregnant" just sounds pretentious and stupid.
But don't take my word for it; here's Mila Kunis:
There is nothing wrong with men who want to show their excitement about becoming a father or who want to show their solidarity with the woman who is bearing their child. There is nothing wrong with men saying things like "we're expecting" or "we're going to have a baby." But men need to stop saying "we're pregnant." Because you're not.