Frank would have moved out of the way, really (he was the man, after all. It was only polite to let ladies go first), but he was simply moving too fast, trying to keep up with Mary who was significantly taller than he was. Instead, he soon felt his knees hitting the concrete as he moved right at the same time as the woman did. They went in opposite directions, but the sudden movement still tripped up Frank's legs.
He saw the scraped knee before he felt it. It didn't hurt much (and he wasn't going to cry about it. Not in front of his sister.) but he'd ripped his school pants and it was just one more thing that he and Mary were going to get in trouble over. He wanted to curse, much like his father always did, but again, it always sucked when there were girls around.
"OW!" He yelled out instead, reaching down almost instantly to touch the blood as little boys were wont to do.
"Are you okay?" Mark asked, a look in her eyes saying what they were both thinking, 'we're going to be in SO much trouble.'
"It's fine. Don't help me!" After a moment Frank got up by himself, battling his sister's hands away the whole time. He looked at the woman he'd nearly run into. "I'm sorry, Ma'am. I should've looked where I was going."