Do you think this is because she is the only one on his team that is military? He is bound by rules and regulations that he is not with Teal'c and Daniel. He is watching after her as much as protecting himself.

Well, and she's the only one who pays attention to his attempts to distance himself. He tried that with Daniel in the very beginning of Children of the Gods (The walk-right past like you don't care approach) and Daniel just kinda ignored it.