Here's one that's hard to say out loud, if not impossible:
"When I'm in the kitchen, please just relax. I appreciate your kindness (and when I said 'thank you' that's what I meant) but please don't treat me like a guest in the house where I live. I came to make myself a cup of tea. I don't want to have to prepare myself for a barrage of generosity every time I think about coming down the stair."
That's not possible. It can't be said
not without arming an emotional time-bomb.