In last few weeks DS (4) has started really pushing boundaries with behaviour, being cheeky and also pooing pants. We're expecting DC2 in a few weeks, which he's very well aware of and is excited about. He's starting school in September so that's another unknown big change coming up. So yes, I know it's likely there's a connection but wondering what others who've had similar experiences would suggest.
Examples include showing off in front of friends, prodding, hitting and kicking other children, point blank refusing to do certain things he's always done before etc.