Dinner had been eaten in uncomfortable silence at the table near the covered window. Afterward, a grim Sheldon took himself off to the bathroom to brush his teeth and clean up. Penny put the dinner's garbage in the trash bin, and then moved the whole thing out into the hall. Sheldon's senses were probably more sensitive now. When he came out, he stared at her for a long moment.

"I haven't been without some kind of sense inhibitor since I turned 15.", he said, "It's terrible. Everything is too loud, too bright, and smells awful."

"We don't have to do this, Sheldon.", Penny said. "You can take your inhibitors, and I can just take off, or maybe just turn myself in."

"Have you changed your mind, Penny?,"he inquired, eyes focused uncomfortably on her face, "Do you want to go into the military?"

"No, but Sheldon, I don't want to - gawd, force you into something you can't get out of.", Penny was surprised to note that she was actually wringing her hands. Sure, she freeloaded on the food, wifi and occasional monetary help from the guys, but this really felt like going too far.

"I wouldn't have offered, Penny, if I hadn't considered it acceptable.", he said, staring at her like she was a whiteboard covered in equations. "I think they were right about the instincts, because you smell really good."

Taking a deep breath, Penny approached him and gently touched his cheek. "You're nervous, and worried. I can feel it."

"I am, but I'm not backing out.", he looked at her openly and seriously, standing there looking so innocent in his Thursday pajamas.

"Sheldon? How much do you know about the whole Sentinel/Guide bonding process? I mean, they didn't really go into it in Mrs. Massey's class."

"Since my senses came online, all of my research about Sentinels has been angled towards suppressing the senses, rather than utilizing them. The process is apparently sexual in nature, but we can't afford to get it wrong. We'll need a full bonding to prevent the SGC from assigning you to someone else. I don't think it's safe to research from my laptop or yours, so I've asked Wolowitz to do the necessary research and send it to me via encrypted email.", he sat down at the desk, turning on his laptop. "I do have additional security measures in place and am having him send me the information to a new email address. Hopefully, even if they are able to trace it, they will be too late to prevent anything."

He looked uncomfortable, and he twitched every time she moved. She could feel his nervousness, but a new note of arousal was beginning to color his emotional thread. Apparently, the pheromones were working. Her empathy seemed to be working in a similar way. The more intense her awareness of his feelings, the more appealing he seemed. She found herself watching his long, slender fingers dance over the keyboard with fascination.

"Hmph.", Sheldon grumped as his eyes flicked over the email.

"What?"

"Just Wolowitz being Wolowitz. However, it looks fairly straightforward. Apparently there are different procedures and customs for Sentinel/Guide bonding in different cultures, but the commonality is that intercourse, and engaging all five senses in on the Guide should have the right effect. As for the Guide, he just says they have to be emotional open, whatever that means. Exactly the reason I never bothered studying Sentinels and Guides. So much metaphysical hokum."

Now gazing at his profile as if it were the most beautiful thing she'd ever seen, a movement caught her eye. There was a translucent lizard of some kind, maybe about the length of her hand, perched on Sheldon's bicep. Probably he didn't want to hear about it, since Spirit Animals were without a doubt part of the Sentinel/Guide metaphysical hokum. As she watched it, trying to see if it would become more solid and if so, what color it might be, she realized she had never seen anyone else's Spirit Animal, and she had met quite a few Guides since moving to California. They seemed attracted to the Hollywood lifestyle. She'd even seen a few Sentinels, besides the one who had clearly spotted her. Or rather, scented her. However, she had never seen any Spirit Animal other than her own starling. He turned off and closed his laptop, then unplugged it. He had left his cellphone at home, and hers was in the trash bin at her own apartment. This was probably as safe as it was going to get.

He stood, and turned towards her. He looked calm, but so vulnerable.

"Penny, I've never done this before. Coitus, I mean. Sorry, intercourse."

"Oh, Sheldon, you need to stop using those words. Have sex.", his clinical terminology always kinda grossed her out.

"Alright. I've never had sex before."

"But you and Amy...I mean, you've done other stuff, right?", she asked, feeling a bit guilty to be bringing up her friend in this context.

"She kissed me once. It was interesting.", he seemed to be remembering that for a moment, "Penny, can we turn off some of the lights. It is hurting my eyes."

"Sure. Wait.", she was thinking about how the Sentinel needed to use all his senses on the Guide. "Okay, I just want to do something first. Go lay down on the bed."

He looked at her for a moment, "Alright."

He lay straight as a board in the middle of the bed, head in the middle of a pillow, eyes focused on the ceiling. Tension radiated from him, swirling with fear and heat.

"Okay, sweetie. Remember what you said about using all your senses. We're going to start with the easiest one. Sight. So, I'm gonna need you to look at me."

He looked a bit taken aback by that, but grabbed some more pillows and used them to prop himself up so that while still reclining, now he was looking right at her.

Penny took a breath, and pulled her shirt off. Her skin felt tingly, like she could feel his gaze. He looked at her, unblinking, as she slid her Hello Kitty shorts down over her hips. She wasn't wearing underwear. Penny wasn't shy, by any means, but usually when she was undressing for a man, it felt more natural. There was passion, and laughter, and play. Like sex was a delightful game that she got to play with someone and they all knew how to play. Sheldon did not know how to play. He had his eyes focused on her face, and it made her feel more exposed than being naked did.

"Sheldon, sweetie. You're supposed to look."

He face was carefully impassive, but with her mind wide open to him, she knew him to be anything but as his gaze trailed down so slowly she could almost feel it. Her lips, neck and shoulders. Then over her breasts, sweeping around her waist and hips. Widening slightly as he took in her brazilian, and then slowly skimming down her legs. Watching him reach her feet, she slowly turned, inviting him to continue his perusal of her naked body. Time stretched out like saltwater taffy as she waited. After what felt like half an hour, he said,"Okay, Penny. I think I've got it."

She hit the light switch on the wall next to her, and approached the bed, lit only by the shaded lamp on the bedside table. The dimmer light made things feel immediately more intimate, and he watched her face intently as she lowered herself onto the bed next to him.