Baby number one gets all the attention. He or she is doted on for months — or years — with no competition in sight. Then baby number two arrives (and often three, four and so on) and relationships change: The first child is no longer the center of attention, and has to learn to deal with his or her younger sibling. Alison Sweeney recently blogged that her son Benjamin Edward, 4, has become almost a caretaker to new baby sister Megan Hope, 3 months, while Soleil Moon Frye said daughter Poet Sienna Rose, 3 ½, stepped up as a big sis and helped to plan her younger sister Jagger Joseph Blue‘s first birthday party.

As many celebrity parents prepare to welcome baby number two, we want to hear your stories.

So here’s your chance to Sound Off! How did your first child react to your second?