In Act 3, does McComas threaten Mrs. Clandon to make the meeting or face that time’s version of divorce court?

I do not understand what Valentine meant at the end when he said, “I might as well consider myself a married man already” when Gloria and everybody around him was taken to the dance floor.

Why does the waiter start out as such a submissive character, get even more submissive when he sees his son, but suddenly “mans up” near the end when the opinion of Gloria commanding Valentine to marry her occurs?

Lawrenzo Lue