"Have you ever noticed that we finish each other's – "

"Lunch?" Mac interrupted with a straight face but telltale glint of amusement in his eyes.

Stella's gaze flickered to the fry she'd just swiped from her friends' plate and rolled her eyes good-naturedly. "Sentences," she finished. She popped the stolen food into her mouth and chewed thoughtfully, all the while studying Mac's expression.

"I have noticed that," he agreed after a moment's consideration. "We spend so much time together that – "

" – it makes sense we would?"

Mac nodded and offered a half shrug. "Exactly."

They stared at each other. Stella's eyebrow rose slightly as it did when she was theorising something for a case.

"Stella?" Mac prompted her.

She didn't answer. She didn't trust herself to speak in the case that she gave away what she'd been pondering over – that maybe there was something more beneath the surface of their relationship than friendship. They were so in sync with each other it very well could be more than that.

He placed a hand over hers on the tabletop between them.

"It's weird, isn't it?" she covered when she realised she'd been silent too long. "I mean, it's weird but it's also kind of…"

He inclined his head. "Nice?"

"Yeah." She ran her tongue over her lips, still wondering about their relationship, unbeknownst to her that he was thinking the same thing.

A waitress came by their table to give them the cheque before she had a chance to say anything. Mac sorted it out and dished out money to pay for both of them. Stella could tell by his expression that he was surprised when she didn't protest. She offered him a shrug. "I'll get it next time."

Alone again, they lapsed into silence and finished off their meals.

"Well," Mac said finally, entwining his fingers together, "that was nice." He smiled softly at her, some of the usual concern he carried around visibly leaving him.

Stella nodded. "Fries and all," she agreed. "Let's go?"

Mac unlaced his fingers, letting them drop to his sides. "Let's go."

They stood up and began to walk back to the lab. As they were about to go their separate ways, Stella smiled warmly at Mac and placed a quick kiss on his cheek.

"Thanks for lunch," she said. "Same time tomorrow?"

Mac offered a shrug, the glint in his eyes betraying his otherwise casual stance. "It's a date."