"They could have killed you if Strange hadn't found you," he argues, letting go of Tony's arm before he can do damage.

"They still could. They could show up tomorrow or, or tonight. They aren't gonna stop at just this. They're gonna kill you. They're just gonna take you away if I don't stop them," he gasps, chest getting tighter and tighter.

He has to stop them. He has to stop them right now because Tony is just human without the suit and if he loses him then that's it. That's game over. Peter can't do it, again.