Sometime during Season 7.
Disclaimer: I hate Pete. I really don't think that his character was necessary and all he did was make people hate him—including Sam. He's basically just a poor, non-Air Force substitute for Jack. We all know this, but I think it's funny that Pete's name was so blatantly Irish.
Also, I only know that Jack's middle initial is J, so as for everyone's middle names…I made them up.
Daniel plopped down in the seat next to Sam. There weren't many people in the mess this early, but he still figured Sam would appreciate keeping the conversation quiet.
"His name is Pete," she mumbled over her mug. She knew she was blushing, but she didn't want Daniel to know that she didn't want anyone to know about Pete. It wasn't a serious relationship, but she hadn't dated in so long that she figured the guys would make a big deal out of it.
"Pete…" He waved a hand, asking for more information.
"Pete Shanahan."
"Oh." He sipped his coffee.
Now Daniel chooses to stick to monosyllabic responses? "Oh?"
"Just…Well, it's a very Irish name, is all…"
"Most likely because he comes from a big Irish family. Why are you making that face?"
His face went blank. "I don't know. What's his middle name?"
"Middle name?" She squinted in his direction. "Why?"
"Just tell me. I know you know it."
"We just started dating—why should I know his middle name?"
"Because he's a cop, your brother is a cop, and you're you. Now tell me or I'll do something to embarrass you when I meet him."
"One, you don't run background checks on people you are in a relationship with. Two, there is nothing you could tell him that would…" He raised an eyebrow at her and she remembered that there were in fact a number of un-classified things that Daniel could mention to Pete. "Fine. It's Ryan."
"Oh." His attention shifted to the mug in his hands.
"Daniel! What is your problem?"
Daniel shrugged. "Peter Ryan Shanahan. Like I said…he has a very Irish name."
"So? Why is that a big deal?" She knew she should feel foolish for being so angry about this, but Daniel wasn't one to question people just for the sake of questioning people.
"I guess it's not."
"No, it isn't."
They turned back to their coffee. The silence should have been comforting, but she got the uneasy feeling that he wasn't quite finished with her. His face had the words 'Ulterior Motives' printed in large letters all over. "Samantha Shanahan. Yikes."
"Daniel," she warned him.
He ignored her. "What's your middle name?"
"I don't have a middle name, actually." She knew that he, like everyone else, would not believe him.
"C'mon, everyone has a middle name."
"No, not everyone. Mark doesn't have one either."
Jack appeared at that moment, making sure that as he sat down, each movement made more sound than necessary. "Mark? Your brother Mark? What doesn't Mark have?"
Sam huffed and Daniel rolled his eyes at her. "Sam claims that she and Mark don't have middle names."
"Really? That's just wrong, Carter."
Sam glared at the two of them. "Yes. But enough about me, what about you two? What are your middle names?"
"Melburn," Jack said at the same time Daniel said, "James."
Sam snorted into her hands. "Sir? Your middle name is 'Melburn'?"
He looked confused. "What? No! That's Daniel's. Mine is James."
"You mean you two know each other's middle names?"
They looked at each other and shrugged. "Well, yeah."
She fixed a disbelieving eye on Daniel. "Melburn?"
"What? It was my dad's name?"
"Oh."
"Besides, 'Melburn' as a middle name isn't half as funny as being called 'JJ'." JJ? Who's JJ? Oh…
"DON'T CALL ME THAT! My mom used to call me that and I hated it."
"I'm sorry, but your parents had to know what they were doing when they named you Jonathan James O'Neill."
It was his turn to roll his eyes. "Of course they knew what they were doing. Mom named me after her favorite writers: Jonathan Swift and James Joyce."
"Who?" Sam looked to Daniel for clarification.
Daniel's mouth twitched. "Weren't they both anarchists?"
Jack shrugged. "Granny was a member of the IRA before her and Pops moved to Minnesota."
"Aha. Everything makes so much more sense, now."
"And what's that supposed to mean?"
"Oh, nothing…" Daniel winked conspiratorially at Sam, who ducked to hide her amusement.
"Whatever. I'll see you guys at the briefing later. Right now I need to go drag Teal'c away from the gym."
Jack tried—and failed—to keep his dignity intact as he walked out. Sam peeked over her mug at Daniel. "OK, what's that look for?"
"I was just thinking… Jack's name is even more Irish than Pete's…" She frowned at him. "Is it the luck of the Irish, or do you just have a thing for names?"
"Daniel?"
"Yes?"
"Shut up."
"Then again, Jack doesn't exactly look like a stereotypical Irishman. He's not short and round like most Irish guys, and his hair's still mostly there—" She startled Daniel by slamming her mug down onto the table and stomping out of the mess. "Wait, what did I say?"