And here I'd always thought it was my ex inlaws, that had the biggest house......she always talked like it was, complaining how small their 4000sf condo in Omaha was..... 
Yeah, they did have a pretty big house, in the Sandhills, just up over the hill from us.
I dunno if it was the largest in town--it may well have been--but it was at least one of the very largest.
They lived on the other side of the hill from us, and going down that hill on the south were two other very large residences, but very old, from circa 1900 or something (the house of your exes was new), owned by then-widows of prominent bankers. One in particular, on the west side of the street, had vast grounds.
But that was in the Sandhills; the biggest house I ever lived in was alongside the Platte River, about 60 miles south.
When we moved up there, the parents looked at three old houses, and decided no, we'll just have a new one built. This new house was the only house around there for years and years and years. Our neighbors were wheat-fields.
Being kind of outside of town, there was always a disagreement about what the street should be named; when we moved there, its monicker was "Sioux Lane," but shortly thereafter it was changed to "Sioux Avenue." Some years later it reverted back to "Sioux Lane," but the parents thought it silly, and always referred to it as "Sioux Avenue" to the end of their days, and I still do.
Incidentally, I never saw so many variations of a name, this "Sioux" bit. I think only a small proportion of the mail we got, had "Sioux" spelled correctly. Correspondents from the northeastern states, including relatives, never got the word correctly.
But going back to the three older houses first examined; two were large two-stories, a little bit smaller than our former home on the Platte River. The third was two stories, not quite as tall, but meandered for half a block. A whole half a city block.
That was the one I wanted us to get, but my father pointed out that the family wasn't going to grow any more, and in fact shrink (because the older children went off to college, got married, moved away, &c., &c., &c.).
I really wanted that house. It was ultimately purchased by a gasoline-station owner, who had 16 children.