The error in the lyrics is the use of the word 'weigh,' which is a homophone for 'way.' Homophones are words that sound the same but have different meanings and spellings. In this context, 'way' refers to a path or direction, while 'weigh' refers to measuring weight. The correct usage in the song should be 'And now you're in my way,' indicating that someone is obstructing the speaker's path.