He wasn't an idiot, no matter what McKay called him after the thing with the Ancient Clone-O-Matic, so John had waited for the right moment to confess his secret. Now, alone in the local's interpretation of a doctor's waiting room for what they'd been told would be at least a couple of hours, he thought it was time. (Ronon and Teyla were busy fulfilling the various cultural obligations that the Raidne insisted on before beginning negotiations; Teyla, as the only woman on the team, was required to perform the ceremonial Dance of Revelation to prove that they had come to trade with no hidden agendas or ill will. Ronon had gone along to observe. John really hoped the high priest had been speaking metaphorically when he mentioned "unveiling all that which is hidden," but Ronon had looked pretty damn smug about being invited.)
Anyway, secrets. Coming out of the metaphorical closet. Though he'd already done that one, really, and all he could do now was hope that the consequences of this exposure would be as pleasant as they'd been before. At least this one wouldn't end with Beckett stammering and blushing his way through the post-mission physical. "Rodney, I'm a siren."
Rodney had been busy typing, but now he looked up. "What did you say?"
"I'm a siren," John repeated patiently. "I thought you should know."
"A siren." Rodney gave him a flat look. "A beautiful woman who lures sailors to their deaths with her singing."
John nodded, pleased that the concept wasn't completely unfamiliar. He wouldn't have picked Rodney as a mythology buff. "Not female, obviously, but yes."
Rodney didn't respond for some time, he just stared. John finally broke the silence himself. "Stop looking at me like that. I haven't had anything to eat or drink since we got here and you checked the air yourself."
"You've obviously been exposed to something," Rodney said, "because you're delusional. I've heard you do "Ring of Fire" in the shower, the only way that voice could kill sailors would be if they committed suicide to escape."
That stung a little - he wasn't *that* bad - but he graciously decided to let it slide. Disputing an insult with Rodney was usually moderately less successful than fighting a land war in Asia. "The singing really only works for girls. For the males of the species things are a lot more... subtle. We just come across as very, very appealing."
Rodney's mouth was half-open to respond when he stopped. And considered. Eventually he said, "oh my god, you're a siren."
John smiled. Then, because Rodney was cute when he was dumbstruck, he went on to prove just how very appealing he could be.
Quite a while later, after Rodney's brain had a chance to come back online: "Hang on- if you know how it works, why do you never see it coming?"