He did his best not to be too obvious about it, but Barney was ridiculously, ecstatically happy when Ted and Robin broke up. He cared about his friends' feelings, of course, but in this particular case he liked his status quo even more. So after Ted let him crow about it for a bit, Barney gave him a comforting, manly pat on the back, the kind that makes the recipient sway on his feet for balance, and headed back inside to the open bar and his own private celebration.
He got his drink, turned around, and found Robin leaning against the wall a few feet away. She had abandoned her bottled water for something a little stronger by now and was wearing a slightly defensive expression that clearly said, 'the bride is drunk off her ass; the bridesmaid can be a little tipsy if she wants.' Barney smiled to himself and walked over. "Good to have you back on the team, Scherbatsky," he announced loudly.
She jumped a little and turned to look at him, a fake smile forming automatically on her face. Her expression relaxed when she saw who it was. "Hi, Barney," she sighed, "What are you talking about now?"
"You know, The Bro Team. The Singles. The Wingmen." He leaned against the wall with one arm and gestured dramatically with the one holding his already half-empty glass. "It's been a while," he continued, sounding a little more thoughtful, "The Bro Code demands that a bro not be overly friendly with a bro's girlfriend. There's no official text on if said girlfriend is also a bro, but I decided to play it safe." He brought the glass to his mouth.
Robin frowned. "We were still friends."
"Yeah, but not really," he said with a dismissive wave of his hand, "We talked and drank, but we never bro-ed out again. And I haven't been invading your personal space or making ridiculously lewd comments like friends do."
She gave him a blank look. "Barney, yes you have."
He paused. "Okay yeah, but not nearly enough," he grinned, and the way he tilted his head and raised his eyebrows managed to make the comment seem filthy. And Robin had definitely made it to tipsy by this point, because she hadn't even noticed him inching forward during the conversation until they were really quite close.
She resisted the urge to pull back and lifted her chin instead. "So this would be you making up for lost time?" she asked.
"Of course," he said in a low tone, expression suddenly serious as he looked her in the eye. Then he leaned forward a few more inches, tilted his head, and whispered something outrageous and undeniably lewd into her ear.
Robin, somehow not expecting it, laughed hard and smacked him on the shoulder, and he took a step back but not far enough to actually leave her personal space. She smiled at him, genuinely this time. "I've missed you too, Barney."
Barney grinned, clinked his glass against hers, and settled back against the wall beside her. "The bros are back," he murmured mostly to himself, "It's gonna be legendary."