This is an annoying trait that my moms husband has. It’s ok to let it annoy you. It shouldn’t be fucking with your day. If he says come here just say I’m doing or in x(watching the TV, in the kitchen, eating lunch, cleaning) it doesn’t need to be super important but it’ll just communicate you’re doing something she he can bring the news to you. It should not stress you out though. Just change the dynamic a bit.