Charlie had noticed it first. Which was strange in and of itself. Everyone would agree that he was the densest of the Eppes in the matter of the heart. So was he just seeing things when Egerton would let his eyes linger on his brother longer than necessary with a calculating expression? How Don would stand just a bit closer to Egerton than anyone else. He ran the statistics of the match over and over again. Charlie didn't want to be seeing things or thinking about things like that about his brother. But all the statistics, all the math pointed to one conclusion, one that didn't fit in with Don's actions, his flings, his dates. All the numbers pointed to Don being gay, or at least more bi than normal. But before he could approach the subject with his brother Egerton left.

If Charlie was going to be honest with himself he would have to admit to noticing this strange behavior with Agent Billy Cooper. Only when Cooper was in town helping them, Cooper seemed to know about Don's subtle changes, and played along with them. Egerton just looked like he was trying to figure out a puzzle.

When Charlie shared his observation with David, David just laughed and said that Charlie wasn't the best person to judge Don's preferences. David made it a point to point out that the talk at the water cooler was that Don was very talented in-between the sheets with woman. Charlie blushed harder as he walked away and saw said water cooler. He really was not the best to judge his brothers preferences.

Then Robin Brooks appeared out of nowhere. Charlie was surprised when the relationship lasted for so long. Usually Don would have dumped or "ran away" by then. When Charlie heard the talk about Liz and Don, he was distressed. Don had made a point to make sure he never cheated on whoever he was dating at the time. When the truth finally came out that it was Robin who broke off the relationship Charlie was even more astounded.

He brought it up with Amita and she just laughed in his face. One of the few times that Amita had ever laughed at him. When she had finally settled down, she had explained that Don was so straight that he made every other man look gay. And that comment had gotten Charlie thinking. What if Don was doing everything that would make him look straight to the point that he was too straight. Men and woman are bi in some way, but Don just didn't poses that quality about him. So, Charlie reasoned, he was either not bi at all, or he was hiding the fact. The latter was true when Charlie found time to crunch out the numbers.

Then Robin was back with Don. They had apparently worked out their differences. Charlie called Robin the next week wanting to talk to her personally. They set a date for a coffee break. Charlie was both apprehensive about confronting her about Don and excited to learn if his numbers actually turned out wrong for once.

"Charlie" Robin greeted the professor. "I was surprised that you called me."

"Yes, well, I have something I want to discuss with you." Charlie scooted his chair closer to Robin.

Robin raised an eyebrow. "What can I help you with Professor."

"Its not really a professional question, more personal than anything." Charlie's hands twitched nervously. "It's more about Don than you." Charlie looked around quickly.

"Shouldn't you be talking to Don if you want to know about Don." Robin asked running her fingers over the coffee cup.

"Well I'm actually hopping I'm wrong." Charlie dropped his voice and tilted his head in that way of his.

"Wrong about what?" Robin stopped moving giving Charlie her full attention.

"I think that Don is more bi than most people. And I've done some equations and they all say the same thing." Here Charlie looked at her pleading. "You'd tell me if I'm wrong right? I mean no one else has noticed anything and both David and Amita think I've lost my mind."

Robin had only raised her eyebrows slightly. "You are the first person to catch on without Don telling you. Actually I kept wanting to watch Iron Man and Don didn't seem to mind watching it either and I asked him about it and he said he liked watching Robert Downy Jr. especially without the shirt."

Charlie had buried his head in his hands at the last part. "I didn't need to know that." Charlie whined.

"And that's how I found out his preferences." Robing continued like Charlie had not spoken. "He only told me that two days ago. How'd you figure it out?"

"These things Don did differently when ever he was around Agent Cooper and Egerton."

Robin perked up. "He likes Billy and Ian?"

Charlie blinked at her use of the men's first name. "Well I noticed it with Egerton because he didn't seem to know what Don was doing. Agent Cooper played along with Don."

"Wait what sort of things did you notice Don doing differently?" Robin interrupted.

"Um, he would stand a bit closer to them, sometimes he'd look longer at them or pair himself up with them." Charlie tilted his head again. "Why are you so exited and taking notes?"

Robin looked up from the napkin she was scribbling madly on. "What, oh, um, its like why guys like to watch two girls go at it." At Charlie's blank expression Robing sighed. "Ok, think of two women you would really like to shag. Then imagine them shagging each other." Robin smiled at Charlie's mix of knowledge and utter horror.

"You think it would be hot if my brother was having sex with another man?" Charlie's voice went higher to match his expression.

"Umhum. Just imagine Billy or Ian naked and sweating with Don, oh wait Billy and Ian with Don." Robin seemed to be lost in her own personal world.

"But if you know Don isn't really into woman, then why are you with him?" Charlie called back her attention.

"Because he wants kids and a family. But he still wants to be able to have some fun. So he and I talked and he wants to have kids with me, and I want to watch whenever he has some fun." Robin looked at Charlie's slightly sick look and smirked. "Hey, you asked."

"Yea, now I wish I never did."

"Just don't tell anyone." Robin leaned forward in her chair. "It was a pleasure talking to you, now I must find my boyfriend and ask him a few questions." Robin got up and left the coffee shop.