Apparently this was Rob's way of seeking revenge on his family after they threw him a baby shower and didn't invite the woman actually carrying Rob's baby, Blac Chyna. Plus, things have always been tense between Rob and Kylie because Rob is engaged to his half-sister's boyfriend's baby mama. Thanksgiving is going to be so awkward this year.
Sure, it is seriously messed up that they did not invite Blac Chyna to her own baby shower, but to put your 19-year-old sister's phone number on the internet is a whole different level of evil.
Maybe you should crawl back into your mansion for a few more months and think about what you've done, Rob.