Furtive (adjective) چوری چھپے، خفیہ، مکار، چپکے سے

attempting to avoid notice or attention, typically because of guilt or a belief that discovery would lead to trouble; secretive.
Example: “they spent a furtive day together”
Inadvertently (adverb) انجانے میں، بھولے سے

without intention; accidentally.
Example: “his name had been inadvertently omitted from the list”