He didn't want to leave, that much was obvious from the way his eyes were trailing her, she liked the feeling, liked it a lot. He didn't want to leave but his loyalty to Dean was making him. And now that Dean knew she was in Lawrence it was going to be a constant battle for Sam's attentions, unless Dean was getting laid, he needed to find some tramp in the city.
Asking her if she was going to be okay, in an admittidly cute attempt to stay longer just added to her resolve to not let him leave, but she wouldn't beg.
"I'll be fine, I mean sure the place is private, and sure its bigger than the backseat of a car, and sure you wouldn't have to stay the entire night, but...I mean Dean needs you. You should go sit and watch him brood for hours before you finally crash out"
She turned to face him a little more, her top riding up just slightly at the hip as she did.