Steve frowns deeply once he notices her eyes shining. He has to reassure her even if she may not need it. "I know you're a good woman, Pepper. People don't just do the things that you do for the good of the world to look good. You mean them." It's why he admires her. Pepper Potts has surely done more with her smarts than Captain America ever did with his shield. He visibly struggles with what else to say until he opens his mouth again a moment later.
"I hate that it did that to you too. I hate that I doubted what I know about you because of it. I want us to be good. I know you must know that I consider you and Tony my responsibility." He hasn't been subtle about it. Any time someone looks at them the wrong way he hovers like a well-trained pet waiting for an attack command. "But, I want to be your friend too. Can we be? Can we move past this?" He looks hopelessly earnest like he truly believes she'll say no. He did throw quite the dramatic hissy fit that day. Yeah it came from a place a real pain, but that doesn't excuse him. He let his emotions get the better of him. He's not stupid enough to think there won't be consequences for that.