Let me get this straight. Lassparri doesn't know that Allan Jones and the dame are romanically involved. He finds out, albiet in an awkwardly contrived way, with Allan Jones coming out of the closet before any love-making can take place. He immediately realizes the situation, essentially saying that two's company and three's a crowd. But Big, Stupid Allan Jones takes offense at this and PUNCHES HIM IN THE FACE. Yes, Allan Jones is going to get his big break in opera, just as soon as he stands trial for assault.
Allan Jones, the supposed romantic lead, is the most obnoxious and stupid character in the film. He can't even hold an Italian accent. I'd sooner believe Groucho is Italian. Lassparri does have class. Granted, he expresses it through bizzare sexual rituals involving sailor costumes, whips, and Harpo Marx.
Hey, gj3123, did you even watch the first half of this film? It was established in the beginning that Ricardo and Rosa were an item and Lasspari knew about it when she turned him down for dinner. As for your comments about "Big, Stupid Allan Jones" (subtle touch) and Lasparri's "bizarre sexual rituals," I'd tell you to get a life, but it's obvious you're more in need of a funny bone. It's a comedy!
And, yes, Lasspari deserved to be decked.
gj3123 is nothing but a troll, as proven by his constant referring of Rosa as "the dame".
gj3123, you are treating the scenario as if it were a realistic encounter in the 1990's.
Lassparri's comment was a direct insult to the lady -- he suggested that he was interrupting a 'boudoir' engagement between a young lady and a man, which was, in modern parlance, like calling her a slut -- or in even more modern parlance, a 'ho'.
There would have been no confusion in 1935 that the sock to the jaw was warranted -- to do less would have been unmanly.