I thought the one husband was an a$$

Well, if you came back from a trip and found out that your wife was pregnant, and she told you it was due to a mysterious force or a space alien, wouldn't you have trouble swallowing that story.

He eventually warmed-up to the idea, anyway.

"IMDb...you will never find a more wretched hive of trolls and douchebaggery"

His wife was the first to be confirmed pregnant, and the only one known to be pregnant when he returned from Japan. Prior to his return party scene we only see the girl in church crying, and Linda Kozlowski nauseous. So no it wasn't known that there were a large number of pregnancies, or that they were linked to around the same time as the blackout, that wouldn't be revealed until a few scenes later. He made the decision to move out even before the town meeting scene. I don't think its accurate to call the circumstances bizzare either. Most of the women were married, with the exception of the one girl who is allegedly a virgin.

You could even argue that all of this irrelevant anyway. The one thing he did know for sure is that it isn't his baby. That alone is enough for him to walk away in my opinion, but he eventually came around anyway.