Molly & Liam
Of course, the dress wasn't the reason. Sure, he thought it was super pretty and all that, but he thought she was pretty in everything. It was more that he decided that he needed to stop being stupid and think of himself and Molly instead of their dads.
"Yeah, really. I mean, if you really want to."
Because he did, but he'd never ever ever want to do anything that made her feel at all uncomfortable.