One side of Arthur's lips curled up. If neither of them had voiced it, Arthur still wouldn't have done anything with anyone else until he knew for certain what he and Eames were or what Eames wanted out of this. Besides, as he had said, unless they both knew it was a one night thing or a short term situation, he was fairly monogamous. "Yeah, I guess so -- unless you have anything to say on the matter," he said with a smile. Though from the tone of Eames' voice, it didn't seem like he had any qualms about it at all.