It's totally a line, but she laughs at it anyway. Billy has a way of saying completely cheesy things and still sounding entirely genuine, which she doesn't think she's ever heard anybody else be able to pull off. Isabelle moves into his arms easily when he tugs her closer, sliding a hand up his chest as he kisses her back. It would be easy to just stay here like this for the rest of the night, but eventually he pulls back and keeps walking, and Isabelle follows, trying not to be too put out.

She's definitely better at parkour than him, but she thinks that's what comes with a lifetime of training, so she can't really hold it against him. He's being ridiculously sweet and Isabelle doesn't really know what to do with all of the things he's saying, but then he gets down on one knee and she feels her stomach twist into knots. Oh, no. She loves him, really she does, and Alec is getting married so maybe there's just too much wedding in the air, but this is not how she wanted this night to go. Isabelle doesn't even know if she ever wants to get married at all, and it's going to make things really awkward in a moment.

"Billy, no," she says firmly, shaking her head and reaching out to try and pull him back up. "I love you, I do, but this is not--" She's not sure how she's supposed to say I don't want to marry you without sounding horrible, so she trails off instead, the look on her face about as panicked as Isabelle ever gets.