I'm a hopeless dancer but this looks like you just screw in a lightbulb with one hand and pat the dog with the other.
In one way, this comment by Darcy is more of a comment about the nature of a Bollywood movie rather than an observation about love, or dancing for that matter. Bollywood movies have a tendency to burst into wild and elaborate song and dance routines in the middle of the script often without warning and the dances are convoluted. Darcy, seeing one of these dances, concedes that he is not much good at dancing - a large concession, mind, because Darcy is a confident, borderline-arrogant man who generally claims more talent than he actually has - but by watching the dance moves of the others, he is able to analyze what they are doing and break the dance down into two everyday movements that he does recognize. This shows him to be analytical, and also shows that he surprisingly has no problem with the possibility of making a fool out of himself.
I will end up living in that rotten house, full of spinsters, with no grandchildren.
Mrs Bakshi is becoming increasingly frustrated with her daughters who are showing no signs of getting married. This is rather socially unacceptable, and Mrs Bakshi wants to be able to show that her daughters are marriageable, sought after and successful, success for a woman in India revolving around her ability to marry well. She is convinced that her daughters will never marry and will live at home for ever. She is also longing for grandchildren, which will not come until her daughters have married. This seems less a matter of conforming to social convention and more a matter of her yearning to be a grandparent.
