No you see, this isn't "NATO expanding up to"...
Countries are sovereign to choose their allies. And countries in eastern europe are asking to join a defense alliance against Russia.
Serious question, have you considered that number 1 no one is forcing eastern europe countries to join this alliance, and number 2 WHY do they want to join it? If you haven't, I'll tell you the answer: What is happening in Ukraine and what happened in Georgia and Chechnia is EXACTLY the reason why these countries want join NATO.
NATO isn't expanding up to Russia's borders. Russia is scaring every country it borders, so they're doing something about it.
Oh look, Finland and Sweden are joining NATO https://www.nato.int/cps/en/natohq/news_197737.htm
Because OF COURSE they do, because otherwise they might be next to be invaded.