In the interest of anonymity this might seem vague.
DS is having a party, he has 10 or so guests including his younger brother. One of the party guests is singling DS2 out and being quite cruel - winding up, calling names etc.
WIBU to say this to child's mother or should I just leave it? Suffice to say there will not be the sleepover DS keeps asking for and I'll discourage invites to this child again. This is, of course, DS's 'best' friend. 