While most of us are more than willing to tell a little white lie to protect our loved ones from having to reveal a secret about their identity that may ruin their repuation or their family dynamic, lying for an acquaintance is a pretty big ask. Neighbors, if you ever even speak to them other than a half-hearted wave in the hallway or enthusiastic nod in the driveway, are usually not the people you're going to pull an elaborate husband-swapping charade with.
So, when an angry husband decided to consult the internet's moral compass of Reddit's "Am I the As*hole?" about whether or not he was wrong to refuse to lie in order to protect a secret for his neighbor, people were eager to weigh in.
My husband (42M) and I (31M) live in a nice apartment, we aren't really friends with our neighbors, we're polite but that's about it. Our upstairs neighbor Kelly is a lesbian (closet, she only told us because she assumes all LGBT+ needs to be friends) who's never told her family.