My DS1 has had a couple of sleepovers at Nana and Pa's (my mum n dad) but I think he was almost 2 when he first slept away. We went to a wedding when he was about 15 months and just weaned and my mum stayed at my place for two nights while we were away. He now has a "special bed" (slumber lounger folding bed) especially for sleep overs and sleeps in my parents room, they ALL love it. I'm being induced with DS2 next week and he'll spend a few night with them.