Many of my wives bf's have been my buddy's I served with while in the military. Quite a few of them, my wife, and I, would have loved having their babies.
Unfortunately, my wife was born with a form of PCOS (Polysystic Ovarian Syndrome). She simply doesn't produce an egg. Many doctors have told her it is literally impossible for her to get pregnant. Nevertheless, she still feels the urge.
So, yes. There have been many times, in our past, where my wife was actively trying to get pregnant from her bf. I would have been excited as hell, if one of my buds got my wife pregnant.