article_snippet: Dustin Johnson's happy family life with Paulina Gretzky (left) could spell trouble for McIlroy (right) on the course .
article_snippet: Paulina Gretzky gave birth to son, Tatum, in January .
article_snippet: Paulina Gretzky and Dustin Johnson share a kiss, while Tatum watches, after Tatum victory in Miami on Sunday .