If I need to see a child or young person alone I will be direct and say “Please will you leave us” or “I think I need a conversation with Lucas now”. You need to own it and name it. I say something like “I’m going to talk and then at some point we (me and the young person) are going to have a chat alone and then we’ll feed back to you (the parent) about what’s happening” so the parent doesn’t really have an opportunity to object. It’s about showing the parent that the child is alright with me and that they don’t really need to be here.