A 15 year old in my class said two days ago, quite unabashedly, 'My dada (elder brother) is three months older than me.' When I observed that that is biologically highly improbable, she looked blank, and was demystified only when a few friends who had caught on faster explained it to her over giggles. She had meant her cousin, of course... most Bengalis refer to cousins like that, rarely pausing to think about complications it can cause.