Wouldn't Gaston have been ostracized?

There was a reason that men did not marry courtesans - to keep their inheritance. A gentleman did not work in those days, he simply invested in land and others worked it. The way to keep a fresh flow of cash a gentleman married a lady who came with a dowry. If he did not he would be ostracized, or worst yet - disinherited. In real life at that time, I do not see Honore' without a wife (unless Gaston's brother was the eldest and the one to inherit so it really might not matter as much.) In the biographical movie about Josephine Baker, she is told that her French lover cannot marry a woman who has no "family" (i.e. no blue blood) I think Gaston would have married Gigi anyway, because he was bored with his parents, but I think his parents would at least have had a conversation about disinheritance. As a matter of fact, if Gaston was in his 30's he might have already been married.