Have you noticed your child's behavior going all the way downhill when their sibling has a friend over? You may relate to this week's question from our Facebook group: My kids turn into monsters when their sibling has a friend over. I have a girl and a boy, and they both do this. Other than trying to get the other sibling out of the house, or to have two playdates over at the same time (which is hard with Covid), any tips for quelling this behavior? A playdate’s mere presence can cause friction between siblings, causing the sibling without a friend to become overly attention- seeking, and the sibling with a playdate to cry, ”Mom! He's annoying us!" Firmly address expectations before the playdate by saying something like, "We seem to get into a bad dynamic between you two whenever your sister has a friend over. You can all play together, but if there is a problem I will separate you for the rest of the playdate."  Then be thoughtful about how much of the behavior you can actually ignore. Absent serious conflict, let the kids figure it out. Siblings explore a new dynamic with a third party present: who am I to my sister when this other person is around? It’s useful for them to learn, even if listening to it is annoying to us. Then use the time after the playdate to reflect on what went well–it’s always a good idea to emphasize positive behavior– as well as what did not, and reemphasize your your expectations are going forward. Margaret cites this article by Amy Morin for Very Well Family in this episode. Special thanks to our "Question of the Week" sponsor: Jane.com is a boutique marketplace featuring the latest in women’s fashion, accessories, home decor, children’s clothing, and more. By shopping at jane.com, you support small businesses, 1500 of which are women-owned. And you will not believe the prices! Visit jane.com/laughing. Learn more about your ad choices. Visit podcastchoices.com/adchoices