Who can explain the 'The Little Tiger' reference?

At his wedding banquet, they ask his bride which of his compositions is her favorite. She answers the "The Little Tiger" and everyone laughs except for Tchaikovsky who looks morose. Why did she say "The Little Tiger"? I've looked through his musicography and he doesn't seem to have created any such composition. I'm also aware that his wife, despite having originally told him she was in love with his music, had never actually heard any of it (much to his disappointment). So was this maybe a reference to a composition of some other composer or just generally demonstrating her ignorance? But why tiger? Or was it a joke/pun that only works in Russian?

Surprised, by the way, that the film never seems to reference T's homosexuality.