I grew up in a japanese community in Brazil... even even here... believe me.... they are THIS much of a gossip intrusive kind of ppl XD.......of course they'll get shunned cause japanese can't keep out of others ppl's business if manga are to be believed. i just hope you don't talk about this incest/half-sibling crap irl and just look the words up cause this is fucking embarassing.
So wait, are you really saying that siblings formed though marriage are not considered legally half-siblings? In your country is different or you are just in denyal?