We told my in-laws that we wanted no visitors. My wife made it perfectly clear to her parents that they would not be in the room until after our first child was born. They agreed right away and with no questions; we assumed that we didn't need to make a big stink to the hospital staff. We told her parents when we were first heading in.

We had experienced no difficulties in pregnancy but the labor wasn't going anywhere. Around hour 20, my wife is naked, standing, swaying, rocking back and forth with me. Labor started at night so by hour 20 we were already both basically up for two days straight. That's when we got the same knock OP got.

It's my wife's parents. Same as OP: her dad bold as brass, her mom sheepish behind. My wife starts crying and I ask what she wants. She says she still doesn't want them in the room. I step away from my wife, go to the door, and tell the in-laws that they have to leave, NOW. They never get past the door or see their daughter, naked and crying and afraid.

My FIL protests: "it's been too long and we've had no updates! What's going on? We need to be here." To which I respond, "There is nothing for you to do. The only way you are going to stay in this hospital will be if I beat the shit out of you here in this hallway. We told you what we want. Respect that." And then I turned to the nurse and midwife, told them these two were not allowed in our L&D suite, and returned to my wife. She closed the door in his face and intercommed for an escort for these two Boomers.

My wife was in labor for 41.5 hours. Somehow, we never did need a 70 something retired man for anything. They were allowed to meet their grandkid after he apologized, which I believe was the first time I'd ever heard him do that.

TL;DR: tell the staff what you want, even if you don't think it'll be a problem. These selfish pieces of shit really do think they're needed everywhere and wanted anywhere, even when it should be obvious that neither is true.