<text>  For a parent, breaking the news to your only child that theres a baby on the way can be a nerve-racking - but touching - moment. And for one family who decided to film the precious moment, it also became a hilarious home video clip. Mum Megan Williams revealed that her two-year-old daughter Kathryn is constantly asking for a little brother or sister. Breaking the news: Kathryn, two, sits on her dads lap to be told she is going to be a big sister . So she decided to sit Kathryn in her fathers lap, and film her reaction as they told her the news using a special book titled The Big Sisters Book of Waiting. Do you know why weve got you this book? her dad asks. Because youre going to be a big sister! For Kathryn it was all too much. As she digests the wonderful news, she struggles to keep the excitement in - in one sense at least. Helping hand: Her parents showed her a book called The Big Sisters Book of Waiting Little surprise: But her reaction wasnt quite what her parents were expecting . She leans over to her father and whispers, I farted - leaving her parents in stitches . The clip, uploaded to Someecards YouTube page, has had almost 500,000 views since it was published on March 19. In stitches: She leaned over to her father and whispered, I farted - sparking a fit of giggles . 