With due respect, I am not sure that your response is entirely correct. If you look at YD 376:3 the Lashon of the mechaber and the Ramah seem to indicate that there is no prohibition in such a case (Different inferences). While it may be incorrect to do so (and perhaps this is what you meant), I do not think that there is a clear cut prohibition.. If I am wrong please enlighten me..
Date: 1/10/2005 11:13:48 AM
Subject: adoptee shiva
Message: I understand that there is no chiyuv of shiva and no mitzva of shiva for an adoptee. But is there any ISSUR? Surely it is noy ossur to sit on a low stool and refrain from showering. Is it ossur to tear ones clothing? There may be a problem with refraining from pirya v'rivya, if that applies, but surely there must be things that the adoptee is allowed to do even if he is not required to .
Reply: There is an issur of sitting Shiva if you are not required to.