It's because she was so caught up in the game of teasing and counterteasing. When she had something to occupy her brain, it was a pretty good defense against the vision before her. As it is, there was a perpetual blush on her cheeks just from him being on top of her.

"And what makes you think it's..." ...she trails off for a second, rethinking that statement. She DOES watch him a great deal. Really could anyone blame her? He's far too wonderful for words, and ever since falling so hard for him she'd stolen constant glances at him. And heaven knew she appreciated his physique very much.

Yes, that same physique that was right now almost flush against her. ...

Oh. Dear. God. Seriously how could anyone in their right mind -not- appreciate that?

"A-anyway, it's obviously an exaggeration..!" Geez Lucy, get more red and you'll be an apple. Get your mind out of the gutter.